That just says to me that the man was in distress, and instead of dealing with that distress, the police officer allowed him to die, possibly further exacerbating the issue. Either way, it does not paint a pretty picture, but I guess we're just more forgiving of someone preventing someone from living vs taking their life.
That is a difficult question to answer. I imagine there is always a balancing act. Especially if the police have some rule in place, it could create situations that criminals would attempt to take advantage of. However, I have always been of the mind that I'd rather a guilty person walk free than an innocent person not. And there are always consideration of how use of force can affect those who see it, with secondary effects creating, what I imagine, are the more troublesome effects.