Brilliant. The ending of a movie fucked up because a director forgot about physics.
The lengths some people will go to.
Lengths such as making up stuff that didn't happen in the actual film because it suits their conclusions.
It doesn't topple. And saying the kids had to look the same at the end to avoid confusing the audience doesn't wash. First, we've never seen them and we're expecting them to be older so any larger kids would do, and second if that really was a concern the kids didn't need to be shown at all. It could've ended with the passport stamp and no need for the top spin. (Passport stamp - *BANG* roll credits ... did he get a pass or a fail? tune in next year...). Mal (French for "bad", the character's actual name) didn't need to be magically across the street (or courtyard, if there is one that we're not shown) to affect the suicide scene.
Stuff is either done & shown for a reason or the film is a bunch of massive holes, thus a typical schlockbuster and we're giving Nolan far too much credit.