Presumably they did the rally in a popular area, and you can't tell if he walked over to them or was just passing by.
Based on his shirt, there's no way he was just passing by.
Regardless, publicly calling for death to all Jews ("from the river to the sea") is a special privilege Jews get to receive. And no, I don't give them credit for not ripping his head off.
Not saying it's not anti-semitism, but it's much different than "open season on jews" IMO. I understood this thread to be about random attacks on innocent people; not a general anti-semitism thread.