dropped third strike third out

[BretMan]

Either that "more experienced umpire" had it bass-ackwards, or your memory of what he said is a little off.

ASA Rule 5-5-B states:

"No run shall be scored if the third out of the inning is the result of:
1) A batter-runner being called out prior to reaching first base..."

That's the section of the rule that applies here. No run.