I do not think MHFA training would have made a difference. All reports indicate that the police officers deliberately beat the man to death, disgracing their uniform. Why? Because he was a vagrant that nobody cared about, or at least not until he got on Youtube.
Well, this is just speculation. None of us knows what went through anyone's head. But from what I have read, the officer was angry that the victim (who is schizophrenic) did not comply with his orders as he was sitting on a bus stop bench. At that point, the officer held his fists in front of the victim's face and angrily said, "Now see my fists? They are getting ready to F*** you up!" Then the beat down started.
Who knows, maybe this officer would've done the same thing with a white, elderly guy who didn't comply because his hearing was bad, or a clean cut tough guy who was stubborn and just wanted to ignore the officer, but it seems to me that the lack of compliance and the indignation that the officer apparently felt is what triggered him and not necessarily the homeless part. However, if an officer understands that someone who has some degree of cognitive impairment may not respond to commands or may not really understand what the commands are, hopefully would not get angry enough to do something like that if he recognizes that in someone. So, that's the context in which I am wondering if MHFA might've made a difference.
Again, just speculation, but that was what I thought about that case. We have a pretty defiant, don't-tell-me-what-to-do(-or-I'll-sue!, or-I'll-cap-your-a**!) culture nowadays and I'm sure there are many people in general, not just police, who get really angry about that at times. Now we get so easily angered that we often times fail to consider legitimate reasons why people don't do what we want/expect them to do.