Happens all the time here. I throw it in with the parts of gymnastics that aren't really fair, but just a part of gymnastics. I have heard they are even more tough one their own gymnasts and they know what deductions to look for, etc. Not sure I believe it, but I also think that most judges are just doing their best to judge and be fair. And usually there are 2 judges at all events, at least at night meets normal state and beyond, so it balances out if their were any favoritism.
Like I tell my gymmie, gymnastics isn't always fair, neither is life. You just have to accept that if you are involved in the sport.