Well, probably in real life there aren't many players who truly have garbage handling skills. And a player with garbage handling would be an ideal candidate for a person unable to accuarately assess whether their own skill is up to the task of getting the rebound. If you are really seeing it every other possession, then it's perhaps a reflection of big men trainers under training handling.
But I don't understand what you mean by it being a "random even". I'm sure it is random, but even then the handling skill can determines how often it happens. HA might affect the aggregate proportion of misplayed rebounds, but in any individual event, the outcome is random (not equally likely, but random nonetheless).