Here's what my cop cousin thinks: It sounded to me like the cop was keeping calm until the kid started getting mouthy. The cop may have taken a step toward the kid and it sounded like the kid then stepped up to the cop... not good. The cops then took him down. The way the kid was talking to the cops, he could have been arrested for Obstructing a Peace Officer and maybe Assault if the cop thought the kid was going to hit him or spit at him.
The kid was upset because of the 45 minute wait and claimed to have called the station and spoke with the desk sergeant.. and even left a message. Is this a large city? Why did the kid have to wait? Maybe the cops were on a hostage call or investigating a domestic disturbance or a robbery and couldn't break away. Who knows? The cops normally respond to a call as soon as it is dispatched (everywhere I've worked) and may have to delay response to some calls because of more important "priority" calls. Whatever the reason for the wait, the kid was out of line. The cops didn't raise their voices until the kid was on the ground.
And don't call a cop "bro"..... I hate that.
We all know what a big fan I am of cops. Yet, with a couple of areas of disagreement, I think the cop was largely in the right here, ftmp. Yes, he could have de-escalated and told the kid, "You're this close..." instead of escalating, and "I don't run on your timetable" rather than a simple "I can only do one call at a time and I came as soon as the dispatcher sent me" set them in opposition at the outset. But the only real aggression I saw before the takedown was on the part of the caller. He, like the cop said, postured aggressively.
And I don't think that just because it was to a cop. Had he postured like that to either of us, or if I do it to you, that's assault, and when the bump comes into play, then it becomes battery.
Even though the cop might have done a couple things differently, I gotta go with the cop on this one.