As a D7 high school football coach, I've seen my share of bad calls...lol. The most glaring ones were 2 years ago when in 2 separate games we were trailing by single digits in the 4th quarter. In both games we forced a fumble on defense and during the return there was a "inadvertent whistle". Both times the whistle happened during the return. Both returns went for go ahead TD's, but because of the inadvertent whistle, they awarded the ball back to the offense to replay the down. We lost both games.
In the second of those 2 games, there was only 2 minutes left. After the inadvertent whistle play, the opposing offense replayed the down and committed a false start penalty. The officials remarked the ball and wound the clock, giving the offense a new 25 second clock. They continued to false start until they ran the clock out.
Another game (almost 10 years ago) we were on defense and was winning the game. It was 3rd and 7 and our D tackle got a great jump on the snap. At the snap of the ball, the back judge threw a flag towards the line of scrimmage. We sacked the QB for a loss of 5. I thought they were going to call offsides, but was mad because the back judge can't see if anybody is actually offsides. The white hat waived the flag off and said we were going to replay the down. There was no whistle. Our head coach told the white hat that "it is either a penalty on them, a penalty on us, or it's 4th down". They replayed the down, picked up a 1st down and eventually scored. We won the game, but I thought our head coach was going to jail!