actually this is incorrect. I just watched this play around 40 times from the two diff angles available. I slow-mo'ed the slow-mo and advanced things frame by frame forwards and back and here's what I saw:
As the play starts and Loseman drops back Wilfork beats his man (#67?) and is surging through the line.
As Loseman sets and is releasing the ball 67 slides down Wilforks body and gets him around the lower legs/ankles
Wilfork had the forward momentum going but as he's tripped up he starts to go down and his body twists to the side, probably from the way he was running when his ankles where wrapped up.
By the time his elbow goes out he can no longer see Loseman, his head is fully rotated toward the sideline in the direction that the rest of his body fell.
The way his elbow went out was very indicitive of how I would brace myself if I where to fall unexpectedly that way - if you're not falling flat then you can't use you're hands to brace.
anyway, that's what I saw in my analysis of things...not that I expect it to change anyones mind on anything