What I’m saying is that they almost certainly would not have been able to “get the bad guys” without being shot themselves, unless the tactic was machine-gun emplacements turning everyone into hamburger, with the side effect of starting a shooting war nationwide.
I think you have a very weird and wrong idea of what "collateral damage" means. Actually, the police should avoid collateral damage at all cost, even if it means not catching the bad guys.
I think he refers to the fact that there's been (supreme)court cases about this that generally rule in the polices favour saying they're under no obligation to protect, etc.