Sorry I can't remember where I found this, but it is very curious indeed. Starting around 1:26 you see what appears to be Israeli Arabs waving the Israeli flag (you can hear allahu akbars in the background). Some are wrapped in the flag. There are also calls of Bisrat H'shem! (Very Israeli)
To me it looks like typical sports fans having a great time rooting for their team (politics aside) but I don't speak Arabic.
Are there any Arabic speakers out there who can provide a bit more info on this clip?