[bbartlog]

Folding here is a mistake I think. AA2 is very strong even without the fourth card. I would call (and probably jam most flops).
If stacks sizes with MP were reversed I would raise. Threatening him with elimination should increase fold equity on later streets.
Full analysis would require a knowing all the stack sizes and payouts, but unless this is some sort of satellite where top five places pay and everyone else gets consolation prizes I don't think it makes a difference - you shouldn't have folded.