You should have apologized and told them that you were drunk, and didn't realize the mistake you made. But assure them that you'll half the bottle before the next game.
Parents are idiots I umpired High School and lower levels baseball thru college. I went thru the certification process which wasn't too hard. For a kid in college teh money wasn't bad liek $35-40/game for varsity sports. But the parents sucked. They always complained. 99% of the kids were cool, especially the catchers. I would ask them at times, hey did I miss that one (ball or strike) and they would give me an honest answer and generally I coudl joke around with both the catcher and the hitter. They knew it was a game, but the parents just complained about everything. If they thought I missed a ball-strike call int eh 1st inning some of these folks would talk about it all night long.