This guy is not very bright. If you see something this patently offensive in public, by all means record it. However, that they are so arrogant that they are doing this in public likely means that they think they can get away with it.
And, if they think that, whether or not it is can, they may also think they can beat the snot out of you and get away with it as well.
The Mohammedans need to be exposed for the vile racist antisemites that they are. That said, I would have invited a few friends with me prior to a confrontation...