Here are some of the tons of errors found in p2p.logs while spamming.
At first:
2015-09-28T07:02:09 p2p:message read_loop process_ordinary_mes ] client rejected message sent by peer 127.0.0.1:62015, {"code":10,"name":"assert_exception","message":"Assert Exception","stack":[{"context":{"level":"error","file":"db_block.cpp","line":534,"method":"_apply_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:02:09"},
"format":"(skip & skip_transaction_dupe_check) || trx_idx.indices().get<by_trx_id>().find(trx_id) == trx_idx.indices().get<by_trx_id>().end(): ","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":592,"method":"_apply_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:02:09"},"format":"","data":{"trx":{"ref_block_num":65467,"ref_block_prefix":2922805723,"expiration":"2015-09-28T07:02:48","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:03:43","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["1f17bdb09411ca7eeaf6c7e28b81222ae240c68dddd71d4ce6a68049c38b9429420e5ab73e01ca705fa52ced97a1b723069eac4c8fb3683df09ae6e168d8ce5a87"]}}},{"context":{"level":"warn","file":"db_block.cpp","line":214,"method":"push_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:02:09"},"format":"","data":{"trx":{"ref_block_num":65467,"ref_block_prefix":2922805723,"expiration":"2015-09-28T07:02:48","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:03:43","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["1f17bdb09411ca7eeaf6c7e28b81222ae240c68dddd71d4ce6a68049c38b9429420e5ab73e01ca705fa52ced97a1b723069eac4c8fb3683df09ae6e168d8ce5a87"]}}},{"context":{"level":"warn","file":"application.cpp","line":434,"method":"handle_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:02:09"},"format":"","data":{"transaction_message":{"trx":{"ref_block_num":65467,"ref_block_prefix":2922805723,"expiration":"2015-09-28T07:02:48","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:03:43","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["1f17bdb09411ca7eeaf6c7e28b81222ae240c68dddd71d4ce6a68049c38b9429420e5ab73e01ca705fa52ced97a1b723069eac4c8fb3683df09ae6e168d8ce5a87"]}}}}]} node.cpp:3759
2015-09-28T07:03:13 p2p:message read_loop process_ordinary_mes ] client rejected message sent by peer 104.236.11.171:48991, {"code":10,"name":"assert_exception","message":"Assert Exception","stack":[{"context":{"level":"error","file":"db_block.cpp","line":562,"method":"_apply_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:03:13"},
"format":"now <= trx.expiration: ","data":{"now":"2015-09-28T07:03:09","trx.exp":"2015-09-28T07:03:00"}},{"context":{"level":"warn","file":"db_block.cpp","line":592,"method":"_apply_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:03:13"},"format":"","data":{"trx":{"ref_block_num":65475,"ref_block_prefix":3967048843,"expiration":"2015-09-28T07:03:00","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:04:19","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["1f51cc04c73f2236caa7da4ce80eb8134b5065c632fae74f8f16e839a819f511822a5d375a3457be4fe8028686b6766bcd7c3d77fce19ef35c609c0a15f80fb76f"]}}},{"context":{"level":"warn","file":"db_block.cpp","line":214,"method":"push_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:03:13"},"format":"","data":{"trx":{"ref_block_num":65475,"ref_block_prefix":3967048843,"expiration":"2015-09-28T07:03:00","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:04:19","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["1f51cc04c73f2236caa7da4ce80eb8134b5065c632fae74f8f16e839a819f511822a5d375a3457be4fe8028686b6766bcd7c3d77fce19ef35c609c0a15f80fb76f"]}}},{"context":{"level":"warn","file":"application.cpp","line":434,"method":"handle_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:03:13"},"format":"","data":{"transaction_message":{"trx":{"ref_block_num":65475,"ref_block_prefix":3967048843,"expiration":"2015-09-28T07:03:00","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:04:19","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["1f51cc04c73f2236caa7da4ce80eb8134b5065c632fae74f8f16e839a819f511822a5d375a3457be4fe8028686b6766bcd7c3d77fce19ef35c609c0a15f80fb76f"]}}}}]} node.cpp:3759
2015-09-28T07:04:23 p2p:message read_loop process_ordinary_mes ] client rejected message sent by peer 127.0.0.1:62015, {"code":10,"name":"assert_exception","message":"Assert Exception","stack":[{"context":{"level":"error","file":"db_block.cpp","line":555,"method":"_apply_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:04:23"},
"format":"trx.ref_block_prefix == tapos_block_summary.block_id._hash[1]: ","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":592,"method":"_apply_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:04:23"},"format":"","data":{"trx":{"ref_block_num":65498,"ref_block_prefix":3583879970,"expiration":"2015-09-28T07:04:43","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:05:58","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["20332b3cbc6e337b00ae7b5ebc2e4cf2903fdbd4046558fb51496aee33e45ece6032386c5b3979c85ff1035e6561bb823198fb47f52e2dec224ba48452dd572c53"]}}},{"context":{"level":"warn","file":"db_block.cpp","line":214,"method":"push_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:04:23"},"format":"","data":{"trx":{"ref_block_num":65498,"ref_block_prefix":3583879970,"expiration":"2015-09-28T07:04:43","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:05:58","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["20332b3cbc6e337b00ae7b5ebc2e4cf2903fdbd4046558fb51496aee33e45ece6032386c5b3979c85ff1035e6561bb823198fb47f52e2dec224ba48452dd572c53"]}}},{"context":{"level":"warn","file":"application.cpp","line":434,"method":"handle_transaction","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:04:23"},"format":"","data":{"transaction_message":{"trx":{"ref_block_num":65498,"ref_block_prefix":3583879970,"expiration":"2015-09-28T07:04:43","operations":[[1,{"fee":{"amount":250000,"asset_id":"1.3.0"},"seller":"1.2.17357","amount_to_sell":{"amount":1,"asset_id":"1.3.664"},"min_to_receive":{"amount":100000,"asset_id":"1.3.0"},"expiration":"2015-09-28T07:05:58","fill_or_kill":false,"extensions":[]}]],"extensions":[],"signatures":["20332b3cbc6e337b00ae7b5ebc2e4cf2903fdbd4046558fb51496aee33e45ece6032386c5b3979c85ff1035e6561bb823198fb47f52e2dec224ba48452dd572c53"]}}}}]} node.cpp:3759
My witness node got out of sync here after some seconds.
Later:
2015-09-28T07:22:20 p2p:send_sync_block_to_node_delegate send_sync_block_to_n ] Failed to push sync block 262132 (id:0003fff4f020495812404736ce0e866d4801c01b): client rejected sync block sent by peer: {"code":10,"name":"assert_exception","message":"Assert Exception","stack":[{"context":{"level":"error","file":"db_block.cpp","line":613,"method":"validate_block_header","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:22:20"},
"format":"head_block_id() == next_block.previous: ","data":{"head_block_id":"0003fff3004e3e0a5eed50770023bf74e4c246f1","next.prev":"0003fff36a9b0c61dd3922f19fe1f4a040ff1ae2"}},{"context":{"level":"warn","file":"db_block.cpp","line":495,"method":"_apply_block","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:22:20"},"format":"","data":{"next_block.block_num()":262132}},{"context":{"level":"warn","file":"db_block.cpp","line":195,"method":"_push_block","hostname":"","thread_name":"th_a","timestamp":"2015-09-28T07:22:20"},"format":"","data":{"new_block":{"previous":"0003fff36a9b0c61dd3922f19fe1f4a040ff1ae2","timestamp":"2015-09-28T07:06:12","witness":"1.6.2","transaction_merkle_root":"93a42a8d8c1db93d55ce90defea956544834b5e0","extensions":[],"witness_signature":"20045fae9169b63f0d2f764cfbacf9be2ab7d7044192158b6cf9eca676079b3e302c0f04fa6dd99913c3ef53f7f8423d9809932d3457747dd96fcf920cc920ebbf","transactions":[.....]}