If you're on a religious Commanded War (milchemet Mitzvah), why would you worry if it's a Christian or a Muslim you're killing?
It's all for the glory of god and cleansing of the non-believers.
The IDF just released footage of a commander saying it shouldn't have been done, not to shoot people waving a white flag. Why did they need to be told this now, not after the first 15,000 civilians they killed?
IDF seem to be doing this a lot