Unforgivable? Yes, any rape is unforgivable.

A couple of points:

Not everyone who questions the degree & types of atrocities perpetrated at Deir Yassin is a "denier". Frankly, I would skeptical of a statement by Lehi members accusing Irgunniks in particular of perpetrating atrocities (while they, Lehi, did what, stood by & watched?). That being said, I think both Lehi & Irgun were poorly trained & disciplined, so little would surprise me.

Some of the sexual abuse Palestinian women report likely stems from an army policy of verifying the gender of Palestinians after two male terrorists dressed as women killed several soldiers (I don't have the details in front of me, but I was just watching a documentary on women in the Israeli military discussing this policy). I note in the example of Qalandia checkpoint the sex of the soldiers isn't noted.

Not that this is any excuse for touching. One can verify sex without strip-searches or putting hands on.