I thought everybody knew this. It's not a glitch. They purposely made it so you could do that. You can tell because there are a shit load of teddy bears. Also it's obviously set up as an easter egg. They also have the "Push X to Climb Over" on the obstacles. So yeah just saying.
it's not a glitch, it's an easter egg. Notice the teddy bears at the top. Don't you think it's funny that you're able to actually climb up at those spots and there just happens to be a broken platform for you to ramp up to the top, think about it.