Question on Interference

[sofballmd]

Hi there. New to this forum but I have a question under ASA Rules.

Here's the situation. Bases loaded, one out. Ground ball to third. 3B throws home to the catcher, standing on the plate (we play in a co-ed league where the runner has to go to a mat behind the plate on plays at the plate...not the plate itself). Runner collides with the catcher as the ball gets there, isn't going for the mat, so the call is the runner is out bc of interference. Meanwhile, because of the collision/interference, the catcher dropped the ball and the runner who started on second, advanced to third on the play, then sprints home and scores as the catcher is trying to recover the ball. Mind you, this is all AFTER the interference was called.

I was always under the impression that a call of interference = runner is out, ball is dead, and runners return to the last base touched (important note here, the runner that scored after the interference was on third when the call was made), but the ump said that there is no dead ball after interference?

Was that the right call?