The guy apparently pulled precisely the same stunt at a similar event in the same location when John Paul the Great was there.
An eyewitness reports in the comments at American Papist:
I was there, In ND of Jerusalem. It was very evident how Msgr. George got nervous when Tamimi stood up and approached the microphone... He initiated sayin to the Pope: "Welcome to Jerusalem, capital of Palestine"... so you can imagine the rest of the speech. His tone was very strong, not very friendly. At some point some people (I guess the arabic speakers) started to clap hands supporting him. The Pope's "nunzio", ambassador, in Israel, when directly to the podium to ask Tamimi to end his speech. He ended and walked in front of the Pope and gave him a very distant hand greeting. After that, the Pope left the place, and in the way he stopped to say something and goodbye to Tamimi.It's quite the achievement, actually: getting gentle Joseph Ratzinger to walk out on you. The video's here (French coverage). If it weren't such a serious matter, the look of shame and consternation on all the Catholic faces would be hilarious.