Assuming they were using threshold cryptography, they could have easily configured some redundancy into the system, e.g. by requiring 3 out of 5 people to decrypt it instead of 3 of 3.

It's easy to blame the one guy for losing the key, but he could have gotten hit by a bus or lost the hard drive in a house fire and they would have been equally as screwed. This is more of a system design failure than a PEBKAC failure.

Conspiracy time: Trustee #3 "lost" their key because polling suggested that they wouldn't like the results.

I have no reason to believe that's actually the case, but it's interesting that the org uses a 3 key system to prevent collusion between trustees, but didn't think about how this might enable lone-trustee sabotage.

Skill issue.

Fuuuck... okay people, I'm going to pass my hat around, and you just throw in a piece of paper with the name you voted for.

I've heard of secret ballots, but this is ridiculous!