'Rents

Parents are interesting creatures.
Our dog, Bella, recently had puppies. Before the birthing, she would go into small panic attacks (or at least be really distressed) if we locked her up in the laundry room without our other dog, Bea. Since the puppies were born, Bella has become quite territorial. Bea may not set foot in the laundry room now without serious repercussions.
I work in a public K12 school. It is amazing to see the way some parents have the same territorial fence around their kids. Their sweet babies can do no wrong. And when an adult-in-charge at the school tries to correct a behavior by using preset rules that are readily available in written form for the parent to read, the parent can sometimes make a complete donkey (or jenny) of him (or her)self.
I have been guilty in the past of loudly griping at a coach after a ballgame or yelling loudly from the bleachers at a referee. I like to think I've learned my lesson after apologizing and turning red with embarrassment.
This sort of behavior makes school staff members sometimes comment that "if it weren't for the parents, these kids would be very educable." This attitude is not widespread or constant, but it does pop up from time to time. In reality, constructive involvement of parents can make a child excel beyond their abilities in school, sports, or any other endeavor. It's when the adults in the relationship can't get along and the parent begins to pit the child against their teacher, coach, principal, or whomever may be in charge in absence of the parent, that things go south.
If you have a problem with another adult, take up the situation with that adult in the absence of the child. There may be more to the story than you are aware. Your child may be bending the truth away from the whole truth. Or if the other adult is in the wrong, they are more likely to drop their defenses without the child present.