Not only did I not see the man in the ape costume walk out, I actually said to myself in the back of my head "14. The hell are these people laughing at? 15. 16."
When I first saw it I thought, "Are they trying to make me lose count by having a stupid gorilla walk across the screen?" A good theory I heard is that it doesn't work on the generation of kids growing up with quick cut MTV editing.
I hate this clip though. It's often used in Law classes to teach about the inaccuracies of eye witness testimonies and to discredit them. Counting bastketball passes is somehow supposed to equate to focusing your attention on an attacker's weapon instead of their face.
I've been tricked by this kind of thing before, but not this time. Still it's awesome, in the same way that watching a magic act and being tricked is awesome.