Fun rebuttal: a decent bolt-action rifle in the right hands could have ended that fight quickly.
The main problem on the ground was that patrolmen were armed with pistols and shotguns. They were logistically unprepared for opponents armed with rifles. Doctrine and loadout have changed since then.
North Hollywood really wasn't about "assault" rifles. The bad guys used illegally modified hardware, and the good guys didn't have the right hardware for long-distance confrontations.
Sometimes it’s nice not to destroy the world for a change.