I would always recommend waiting 24 hrs before having a conversation after a conflict.
Was there a mtg between u, coach, son discussing his surgery and discussing how he would be brought along this yr on the team?
If not, that's where the problem occured. All for players only talking w coaches, but when medical issue is involved im all for a mtg w coach and relaying dr/pt info.
Was this yelling/conflict w coach in front of everyone? Really bad if it was. Son also needs to learn to speak up.
Sure you'll talk and straighten things out. Better communication by both parties needed.