Dumb Catcher

[Bandit]

Ok guys I know I'm probally repeating a thread but I can't find what I'm looking for....Runner on 1st, 1 out, full count on batter..I call third strike...catcher drops ball..runner was stealing second on pitch..I know that drop third does not apply because I have runner on first at time of pitch..of course batter takes off for first..catcher over throws first and ball goes into right field..runner that was on first goes all the way to third..after everything settles down I call time and indicate BR is out..Defensive coach wants me to return runner because the BR ran to first when she should not have causing his girls to throw a un-needed ball..I want to tell the coach this what some umpires call a DB (dumb catcher)..but I don't, how would anyone else reply to the coach or have they replied to the coach (in a kind way) ??
P.S. What was really bad was that after the defensive coach asked his question the offensive coach asked why the Dropped third rule applied ??? And this was a Varsity game.