I'd say that's a hella lot more than your typical, tiny, mystery-creak ! Dieselgoat makes a good point about the BB being on everyone's short list, then not being the actual problem, but that does sound like it's in the BB, or the crank.
But, it also had kind of a hollow, woody sound that made me suspect a crack in the carbon frame somewhere. You check that closely already?
How does it sound when you spin the cranks, with no one on the bike? How old is the bike ? (I'm wondering how old it was when the original owner replaced the BB.)