Force or not?

[chapmaja]

I had this play in a girls coach pitch game a while ago.

Bases loaded, 1 out. Batter hits a ball that lands in the batters box, but in fair territory. Catcher steps out from behind the plate, and as she tags the runner steps on the plate. The contact with the plate and contact of the tag appear to be simultaneous. I call a double play, to which the batting teams coach does not agree. First, he argues it was a foul ball, something he could not see from the pitchers plate area. Then he argues it should just be an out on the batter because she was tagged before the catcher stepped on the plate. Finally he argues that it should be a force out, but the batter should be awarded first. After the final argument I told him to head to the dugout and bring his defense out. At least his first two arguments had some validity, but the third was pure foolishness.