From the eyewitnesses, it appears that the call was within the rules. A slam, like all "unnecessary roughness" calls, is in the eye of the beholder. Nobody likes to see an injury or a flaky call/no call that ends up deciding the match. No matter whether this slam call gets made or not someone would think it was the wrong call/no call.

How rough is too rough is not always clear. I see kids do all kinds of things that have no wrestling purpose but are just punishing moves--rubbing heads, forearm on the neck, elbow in the back, head slaps, choke holds, gut-wrenching scissors, and rubbing a forearm across the nose. Just goofy kid's stuff and some MMA submission ideas leaking into "folks style" wrestling. Most coaches don't complain when you call it, but every once in a while they give the "wrestling is a tough sport, combat, sport, etc., which is true, of course, but its not boxing, MMA, or a beat down. It is supposed to be an honorable contest between two sportsman.