Not Jewish and I’ve only been to Israel once, so take my anecdotal experiences with the appropriate amount of salt…

So as with any religion, there are a lot of different sects in Judaism. Some are more radical and traditional than others. The most fundamental Jewish communities in Isreal sometimes have a pretty negative outlook on outsiders and foreigners in general and stick to strict fundamental religious principles. So there are stories of them messing with tourists, like throwing rocks at their cars and spitting at them. I didn’t experience anything like that myself, but was warned about it happening in certain areas.

My theory is that the American group wandered into one of those areas and got roughed up a bit.