He had no expectation to die for that, and he wouldn't. He should have expected to die for attacking a cop; but probably he was already on some serious drugs, besides marijuana, and couldn't think clearly. His actions were highly irrational even for a thug. Thugs are opportunistic predators; but there was no opportunity of any useful kind in beating up an LEO.
He was likely on something although it could have just been adrenaline.
People die almost daily for doing stupid things with no expectation that they might die. Brown fits that category. As proof I submit this: He’s dead.