User blog comment:CutlerBeckett/Is Cotton alive?/@comment-86.87.12.146-20120829072521

There's a 4th possibility:

Maybe the crew (or a part of the crew) stopped being crew and left the ship before Blackbeard attacked it. Because Barbossa didn't mention who were the crew, and who was on the ship at the time of the attack. It could be that maybe Pintel & Ragetti (for example) didn't want to be with Barbossa anymore and left the ship and joined someone else's crew.

(I hope you understand what I mean, it's a little hard for me to explain in English...)