No, he clearly means hitbox. This kind of thing:
http://puu.sh/iOZ4P/79f22f1036.webm
Yeah, hurtbox. The thing(s) where the character can get hurt. Hitbox is something you can hit others with. Hurtbox is where you can get hit.
A list of these could be interesting, but depending on when you count as something to "shift" there could be a really really large list or just one for the most obvious things.
Many characters lean back for some moves.
I think most fsmashes have a little leaning back at first.
Most obvious ones I have in my head are:
- Mario & Doc
- Marth & Lucina?
- Captain Falcon
only a little bit:
- Sonic
- Yoshi
- Ganondorf?
I got hit from Marios (and Docs) fsmashes quite a few times because I didn't hit them because of them pulling back before the hit. That's really annoying. Happened to me really often against Marth in Brawl too (but now he's almost never played anymore).
Then there are the obvious hurtboxshifting moves like dtilts... (though they go lower, not to the sides)
And for specials like the one with Ness who got posted we also have Luigis fireball. He kinda doesn't have a hurtbox on his head while moving it down during the animation.