Slam to the mat?

[officialtony]

Jr. Hi. match.
Red has green ( from behind ) tight around one arm and waist standing in center of mat - no takedown yet. Red lifts green off mat maybe 10 inches, turns him and brings him down with enough force to cause green to exhale like he has been punched in the stomach ( I might add that it was to the side where green's arm was trapped to his body ). I stop the match, signal an illegal hold ( calling a slam ), award a point and, after being sure green is OK, resume match in the nuetral position.
After the meet, the coach questions my call saying I let the crowd groans influence my call ( I'm comfortable that I did not ). I explain my reasoning and indicate that safety is my first concern for the athletes and in my judgement, it was a slam. He disagrees but quietly exits.
My question is, did I follow correct procedure all the way through this and is the call reasonable under the circumstances?