If you have a Jewish state by their own admission and put a lot of meaning into their text. Israel. That state says something is Anti-Semetic. Then someone references their own text to show how they believe something to be their religious right and telling someone to stop that is anti-semitic

If I'm reading what you're saying right, then you think the commenter was trying to mock Israel for their actions in Palestine by joking that Israel holds points about Judaism that justify child murder as sacred (thus telling them to stop would be "anti-Semitic" because their view of Judaism privileges child murdering.)

If I'm reading you right, then

1. that reading is incredibly generous to the point of inaccuracy. Because the context for this is the commenter looking at a post by the AJA, finding a piece of the Torah that reads like it supports child murder, then concludin that because this is part of Sacred Jewish Texts that it is anti-Semitic to tell "them" to stop killing children. This isn't helped by the commenter repeatedly asserting that it is somehow encumbant on all Jews to unilaterally denounce any pro-Israel messaging by any organization with "Jewish" in its name. (I can only guess they think Jews have a radar in their heads that goes "blip" whenever a post like this is made. Otherwise, I don't know how that could possibly be a reasonable expectation.)

2. this assumption relies on a reading of Israel as a representative of Judaism, or that either Judaism or Jewish people are accountable to Israel or it's appropriation of religion. I'm not sure whether this assumption walks the line of or directly crosses into dual loyalty territory, but it certainly sees that line.

It would be like some Catholics killed some gay guys who were kissing and the Catholics said the gay guys where being racist and anti-Catholic.

What's interesting about your analogy is that there is a state that proports to represent Catholicism (Vatican City) that you could have used here, but didn't do so by using "some Catholics" instead. After all, it would be crazy to hold all Catholics responsible and hold them to account to rebut the Vaticans claims for these hypothetical killings if "soldiers from Vatican City" did the killings, no matter what rationale the Vatican would have hypothetically given for them.

I wonder if there is a state and group of people that this analysis should also apply to.