As both cops pointed out—most criminals trying to break into a garage like that, being foiled, wouldn’t simply sit calmly on the front porch afterwards.
The cop clearly went berzerk once the guy took a call and described accurately that he was on his mother’s porch, waiting for her to come home, being harassed by the cops.
The cops didn’t “let this get out of hand”—they completely took it out of hand after he’d been cooperative, giving his id, naming his mother, naming the neighbor, etc.
Any chance that he might have,in fact,been talking to a member of his posse...a fellow ex-con...hoping for help? Are you at all curious about the several interesting observations about the guy found in the link in Post #61?