S&V-not_dead_yet
Talk Tennis Guru
If it had been 1 v 1 it very well could have just been two people practicing together. As is the case when you’ve joined one other party to the court.
But I seriously doubt you and a partner ever go to the court to play singles, then just start hitting with a random guy instead of playing with each other.
The way I interpret @Raul_SJ's telling of the story, the Coach only reacted once he heard the guy giving advice:
and he occasionally was giving us a few tips as we rallied.
This obnoxious coach from the neighboring court comes over and tells the guy, "Hey! Lessons are not allowed!".
That's a surface read and I'm taking him at his word. Perhaps the advice was irrelevant and Coach would have complained anyway. But that's not how it reads.