First, I agree that the police shouldn’t jump in the water to save someone unless they’re trained in water rescues, which most aren’t.
The question I keep coming back to is why something as simple as a life preserver isn’t a fixture in police cruisers?!?
I think the Supreme Court recently addressed this in asserting that police are there to enforce the law, not protect people. There are 1000 ways to die, so they can’t be prepared for everything.