I think he must have been. That lineman was not visible in the replay, but it did not look like the Head Linesman at the top of the screen threw his flag.
You could hear whistles blowing shortly after the fumble. In real time I figured the TD was coming off the board, but had no idea we would keep the ball.
Side note, why didn't those announcers ever look at the refs during the plays? They called that Thomas reception a TD, even though the ref was marking him short of the goal. Then on our 4th down stop of Jefferson, the Head Linesman clearly threw down his bean bag to signal a fumble, but they never noticed. And then on the fumble that wasn't, the refs were waving the play dead before Arkansas even picked up the ball.