The foul didn't seem malicious to me. He raised his hand up as soon as Miller brought the ball towards his head, so it seems like his original intent was to go for the ball. Miller was not hurt and shortly got on his feet. It doesn't look like a flagrant 2 to me.
Miller never brought the ball towards his head. I think the back judge made the call and it does look worse from that angle because West hit Miller from behind and the league protects players from getting hit hard during breakaway fouls. I think his suspension also has a lot to do with West's "dirty player" reputation.
Around the :29 and :35 mark, Miller brings the ball towards his head. It looks worse in real time from his angle, but it doesn't seem to warrant a suspension. I wouldn't be surprised if he also got the "reputation" suspension. Oh, well.