As agent of the HOA, the HOA common property was technically “his”.
If the “kids” were Black, he had justification for fearing retaliation and brandished a gun. It was after all three against one.
There is an issue across the nation with squatters. That is by allowing the “kids” to remain he was in effect setting a precedent for others to come occupy the HOA grounds.
However legalities aside, a more diplomatic resolution would have been preferable
“Black?” You’re really going to go there? In this instance to quasi justify the brandishing of a firearm by an HOA tyrant on children fishing? That’s what you’re going with?