Why would you ask a complete stranger about an incendiary topic? No good is coming from that.
For the benefit of all who have never been exposed to ghetto thugs, this is a typical set up for a robbery or violent assault-- there was no intention to even listen to the answer. It usually starts with asking for a cigarette, money, directions, time, or, as in this case to use his phone. If they smell fear, or believe the risk is worth it, they will move on to step two. Here the victim could not get to his feet in time, and was boxed in so he could not create space-- bad situation to be in. The question was designed to distract him for a moment before he was sucker punched.