From an article on CNN about The Hangover:
But "Hangover"-level successes need to have something extra, says Dergarabedian: chemistry and timing. Indeed, if there's been a criticism of "The Hangover" -- a film that earned generally positive reviews -- it's that its story got a little too loose and unbelievable at times. (Would Heather Graham's stripper character really leave her baby behind without becoming frantic?)
That's the part that the author thought was unrealistic? The escort leaving her baby behind? Not, say, Mike Tyson or the tiger or making $80,000 (?) playing blackjack in a few hours Rain Man style? Interesting.