I don't believe anyone is arguing walking down the middle of the street was legal. The question is, was it really necessary for this cop to make a big deal of it.
Imagine a different scenario. Cop drives by, "Hey guys, could you move to the sidewalk please? Thanks."
A story, a bit late:
Back when I was a freshman in college, after a physics class, my friends and I were talking about...I don't even remember anymore. All of a sudden, a campus cop walked over and, looking at me, said "Excuse me sir, could we talk over here for a few seconds?" I said "Okay." (Somewhat foolishly), and walked over to where his partner was standing. At which point the first cop read me my Miranda rights (!) and started asking me questions about where I was on so-and-so day.
Turns out, a few days beforehand, another person had beaten the snot out of someone over drug money, and someone in class had pointed towards me as the guy who did it. And as it also turns out, we both had a very distinguishing feature - namely a huge afro (it was 1995). As it turns out, there was a guy who was going around, taking pictures of kids with afros - he had given me his car the previous semester. So, by being respectful, the cops had found themselves a decent lead on who this thug was. Now, had they simply run up yelling "Get over here!" like a Mortal Kombat character, I'd have been immediately insulted and embarrassed. I'd have given them absolutely nothing, and might have even been ready to run - or worse, to fight.
So, yeah, I have to agree, yelling "get on the ******* sidewalk!" and then swerving directly in front of them is an absurd way to react to two kids walking down the street - although the past week has certainly shown us that the Ferguson local cops are capable of wild overreactions. And it's bizarre for the police chief to discuss whether or not Brown had pushed someone and stolen some smokes beforehand - if the cop didn't know about it, then it's really not relevant. I had said towards the start of this thread that I thought the local chief was making some good decisions - but I think he messed up here. It'll come across as victim-blaming (it is), and the people protesting him already had no confidence in him (which is unfair, but understandable). What they really needed were the bullet wound locations on Brown, and the report about the shooting rather than his summary.