If this actually happened, this person was an idiot, and I agree that nobody should be like this about any issue on a date- I'd say it would be equally wrong to for someone who identified as "pro-Israel" to act in an equivalent manner to this in the same situation, i.e., to invoke the Holocaust to justify what the IDF does to Palestinians, a group of people who bear no responsibility for the Holocaust- especially the 85% of Palestinians who weren't even born when it happened.

But is is worth noting that the idiot-monster you describe here is nothing at all like the overwhelming majority of people in North America, the UK, Ireland, or Europe who identify as "pro-Palestinian".