Again we go back to the Mo hand .... the pre flop betting went
Raise by Mo to 20k
Re raise by Pete to 45k
RE RE raise by Mo to 100k
Pete just called.
So whilst fairly spewy it's not totally disgusting, Pete doesn't have to have aces here although the only hand Pete might flat with that Mo folds out with this bet is the same hand. He is letting JJ go preflop, QQ is the only grey area where he might fold out pre and maybe die with it on the flop.
I think 150k bet from Mo would of been reasonably unexploitable and when he finds out the bad news 300k is a very workable stack.