My friend and I were playing a multiplayer game (Football to be exact). On of us crushed the other, or something like that, with some crazy results. My guy (Gish) became stuck INSIDE his guy (Gray). I could even somewhat move his guy around a bit, and see the edges of Gish when I tried to jump or go into "stick" mode.
Anyway, just FYI.
Been there, done that 
I think most people already know about this...
Gee, I can't believe I didn't go back 9 months looking for a repeat post! My bad. ;)
It's still a bug.
It's the way their physics engine works.