I don't think he could walk well with a fucking rifle stuck in his pant leg. And this many guns would be heavy as fucking hell. And too many, for that matter.
I'm from Canada, and I haven't been shown that video... We didn't really have much of a dress code either, as long as you don't show too much skin (as in, it's okay to wear a top that leave off a few inches of skin, but if it's the size of a bra, you might get stopped or something.
This is a very insightful video though, I never knew I could hide my guns so easily. Now I won't have to carry a duffelbag with me to school! Hahah. Seriously, this video is hilarious.
Edit: Of course, if you assume the kid took out all the guns, you're mistaken! He has a bazooka up his ass, ammunition included.