[mpyne]

We're effectively always a bitcoin-core bug away from another instance of this. Any bug which could lead to a partition (i.e. where post-upgrade clients believe one chain is the main chain and pre-upgrade clients think a separate chain is the main chain) could lead to this happening again.

Should it happen again you could fix it by either forcing everyone to quickly upgrade (and losing the transactions that occurred on the old main chain post-fork) or by doing what happened here (holding back or downgrading the upgraded clients until the old main chain was the longest chain again, and losing the transactions that had occurred on the new chain post-fork).

What will be even more interesting is what happens if we actually ever get multiple compatible implementations of Bitcoin. As patio11 hinted at, if those implementations are not all "bug for bug" compatible then type of thing could recur over and over again.

So we're left with the choice of remaining with a single reference implementation to reduce (but not eliminate) the risk of introducing partitions due to slight incompatibilities between Bitcoin clients, or to encourage multiple implementations of Bitcoin to reduce the dependency of an entire "decentralized" economy on a centralized reference code base.