It looked to me like a drunken fan was trying to scoop up the ball.
Except his hands were never within three or four feet of the ball. He never made any attempt to bend over to pick up the ball, he was swinging and hit Sheffield.
I agree.
He wasn't even LOOKING at Sheff when he took the "swipe". He was looking down to his left along the wall.
But he still deserves an azz-beating for nearly turning Varitek's triple into a ground rule double, and costing the Sox a run!