Is my partner nuts?

[arkblue]

So I am watching a some games in a tournament with the guy I have umpired a lot of games with. He is more experienced than I so I usually give him the benefit of the doubt. However he rattles off this situation and I tell him I disagree completely.

Runner on third with two outs. Runner on third breaks on release of pitch as the batter bunts the ball down the first base line. The first baseman fields the ball and tags the batter-runner running down the first base line AFTER the runner on third crosses home plate. I say no run due to the fact that no run can score when the third out is a force out. He argues with me that by tagging the runner going to first it is no longer a force. The argument boils down to the point that is it a force play if you tag the forced runner rather than throwing to the base the runner is forced to? I say that the action of the fielder doesn't determine if it is a force play. He states that is wrong. He's nuts right!?

Thanks!