It seems fairly clear to me that this Brown character did commit a fairly serious crime. I'm not sure if it's 15-years-in-prison serious. It's not really necessary to compare it to the other case, either. I mean, I hate seeing people get off easy because they're wealthy, or because they're politicians, or they're the police, or whatever - and that does happen - but it also highlights some deeper issues. I'm sure some people will question the honesty of his claims, but if he is to believed, then he was essentially driven to crime by sheer desperation.
I'm going to go out on a limb here and say that if ever a crime is justifiable, morally at least, it's in a situation like that. Of course he could have done things besides go into a bank and act like he had a gun, but his legal options were certainly limited. This idea that people can pull themselves up by the bootstraps is ... well, this is what it leads to.
I'm certain it would've cost less to somehow help this guy out than to keep him locked up for 15 years, too.