I think I solved it. This is 100% me being an idiot. I used to use the bitcoin-qt client and switched to multibit, importing my bitcoin private key. I then sent the donation from my multibit account but I only backed up the wallet to my original bitcoin wallet, therefore, it split the transaction from the private key of my old wallet and the private key of the new wallet. Also, I (stupidly) deleted the multibit wallet forgetting that I had two keys to worry about instead of just the one in my original wallet.dat file.
Luckily, I have backups that go all the way back to the beginning of this year, so I just restored the multibit wallet from around the same time period as my donation. I'll never say anything bad about apple time machine again
Balance is now showing the correct amount although the transaction scanning hasn't caught up all the way yet.
That was almost a *very* expensive mistake. Back up your data boys and girls...