Thing is...I am not remotely religious. Not a jot. I tend to study more new agey stuff like meditation and chakra's etc. So don't spend any time at all thinking about Jesus, or Mary, other than when they put T towels on their heads at Christmas...which is merely derived from winter solstice celebrations, which are common to lots of religions, as Easter is based on the phases of the moon. So why would my children know stuff about Jesus?
I have never has a problem with this until recently. I don't expect my dd to come home from school with any hint of anti-Semitism, that's all.
DD's dad was brought up a Catholic, and had never heard of the link with bonfire night, as many of the catholic's upthread.
I expect we all know things that others don't, because we all have a different reality...not better or worse, just different.
BUT, this stuff must be taught with very great care, and imparting any mistrust of "the other" can only be harmful.
My ds went to a community school with a very religious Jewish head, and her influence was keenly felt throughout the school, but I must say, never in such a negative way.
I agree with the comments above about where these folk will be going next, and further investigation as to just what happened in these "RE" classes.
I don't care much for any organised religion much myself. I want my children to grow up respecting people, all people, regardless, that's all.