Unfortunately, I am speaking from experience. You cannot win in this situation. If you say anything, you will come across as a whiner even if you are 100% correct. It is not worth it. Just let it go. If it gets too bad, leave the team.
Honestly, part of the reason I quickly ask the coach if I can manage Game Changer is to avoid this crap. Coaches know A) I've been a travel coach, and B) I don't play favorites and am level-headed.
And I'll say things in front of parents to my DD like "Wow kid, you crushed that ball. But I had to score it an error because the SS should have made the play". And yes, I'm saying it mostly so the other parents hear (and can go double-check). I'm proud of my DD and her performance, but I don't doctor her stats.