First off, Why are the police intervening in a suicide? I can see it if other people were at risk but if the man was in the privacy of his own home and wanted to kill himself and was harming no one other than himself than that is his business not theirs. Not saying its right but we don't need the police to save us from ourselves.
Second from my understanding they can not enter without a warrant, so the man was in his rights, now if he handled it properly is still in question imho. We don't know any of the particulars other than what the police said (and I respect all of our law enforcement men and women) but maybe the man was asleep and woken up by the banging on his door and then next thing you know the door is being kicked in.......I think I would do the same thing however when asked to put the gun down and found out what was going on I would have cooperated.
Because if we are made aware of a suicidal person and DON'T intervene, you bet your arse that if they hurt themselves or someone else, the officers/department/city will get sued. They have in the past and lost. Yes, we usually need a warrant to enter a house. However, we are allowed to make entry based on exigent circumstances.
Exigent circumstance in United States law - Wikipedia, the free encyclopedia