I can't fathom feeling the need to shoot 49 times mixed with X amount of mag changes at someone that was not even shooting back.
There has to be a science to this. just like that guy in NY that got pumped full of rounds at his bachelor party by NYC ( think ) Cops.
I've never been a gun fight so my guess is when you hear the other cops guns going off you think it is the "bad guy" shooting back so you keep firing. this combined with some feeling that the other guys are shooting I should be too. like in this example the one guy that fired at least one round from what looks to me to be at least 40 yards away.
Not that the psychology of it excuses the behavior but I think it is something that should be studied.