LOL. It happens everywhere. On the playground, in the backyard, in games. Kids just try to keep it hidden from the folks who would get them in trouble. Unfortunately for this kid, he said it around a boom mic (or whatever that is).
My kid is a frosh football player ... just had a scrimmage against a "city" team in which we whooped up on them. Inevitably, trash talking commenced ... the other team, getting their butts handed to them, start to get chippy. Then the insults start flying, then the insults fly back ... eventually, in this instance, there was one loud exchange that the coaches had to address on both sides.
When I asked my son about it, he said "it was nothing ... it happens all the time, and was happening all game ... I just play."
One time, at our youth baseball complex, when the boys were younger, some other boys had stopped by during a game to watch. They then formed their own "pickup game" on another field ... I walked by that game to use the facilities, and in a 30-second span I heard about 10 insults using all sorts of curse words and mentions of women family members. These kids were probably 12 years old, give or take. No one was upset. It's just the way they communicate and interact.