Another large area where a DAC feature requires human intervention is whenever there is "external conditionality". This is whenever reference to some external source is required in order for the DAC to take certain actions.
An example is the price-feed for bitAssets, which requires a manual feed from delegates. We need to trust and incentivise the delegates to do the best job possible, but how they do this is not transparent to us. Another example would be with insurance, where premiums are conditional on underwriting, or claim payments are conditional on the claims submission and verification processes, which require trust (and proper incentive) in human actions. Voting would require human intervention around identity. I don't know, but I assume Music will have points of human intervention around the production and sales of music tracks.
So far in this discussion we have talked about the need for human intervention in dealing with IPO and equity capital, merger and acquisition capital, labour motivation and handling of funds (delegates), and any external conditionality that a transaction may be dependent on. There may be more if we go on.
So I'm coming to the conclusion that any reasonably complex service cannot be completely captured on a block-chain without points of human intervention.
If we want to open up the flexibility of these DAC platforms to capture traditional industries, I suspect we need to embrace the need for human judgments in certain tasks, rather than trying to avoid them. We can still recognise the need to minimise them as much as possible. And that means using the best tools available to derive maximum security and efficiency from that.
And if we take that step, maybe there is no reason why any service should not also make use of multiple chains?