This certainly looks to me as the follow-thru of throwing a Screw Ball --- Didn't know they were still teaching that to young pitchers - Anyone there to see if that was what it was? ---
http://www.appstatesports.com/ViewArtic ... =211487295

That's certainly what it looks like......Rough on the ol elbow.

His arm is pronating on what is likely a change-up. All pitchers pronate to some degree after releasing the ball, and depending on when the camera shot was taken, it can look almost like they were throwing a screwball. Very hard to see with the naked eye...