You may be naive in believing that “no Catholic teacher or priest has ever taught animosity towards fellow Christians.”
That, simply, is historically untrue.
However, we pray, “Forgive us our debts as we forgive our debtors,” and hope in the present and future truth of your statement.
Sorry you had some bad experiences with your child.
I am a life long Catholic. NEVER has a priest said anything negative to me about fellow Christians. NEVER!
We live in 2 different worlds as far as that is concerned.