lionbaseball, I think that the BU thought that the 1st baseman had somehow touched the base after catching the ball and that is why he called him out.
Swampboy: Thanks for the explanation, but without any attempt at a play by the 1st baseman and where R2 was at the time of the call I thought it was odd that they sent him back to 3rd. I can see why the defensive coach would argue for that.