You also can't blame him from a Jewish perspective for saying they're Nazis. Here's a story so we all get each other. In France my grandmother of blessed memory was hiding from the Nazis YS"V in the house of one Catholic lady who went to church with a lady called Mme. Jambon. My grandmother was a nice little girl so she told Mme. Jambon she was hiding from the Nazis at a house, so Mme. Jambon snitched, maybe for the money, maybe she was scared now that she knew she had to tell or you would be executed, maybe she didn't like Jews, snitched to murderers either way. The lady had left a signal and my grandmother and her mother escaped, and G-d only knows what happened to the lady that saved their lives, may she and her offspring be blessed forever. End of the day, Mme. Jambon would still be welcome in church and listen to the services.
If it was a muslim state and there was a decree to catch Catholics and a Jew sold one hiding out with another Jew, he would never be allowed to return to the synagogue, no one would marry his daughters that heard of it, no one would go to his business and he'd be basically a leper as an informer. The difference here is Catholics can show up in India and offer people to convert, and they are joyful, jump up and down, take the statue next to their other statues and sacrifice to it, yay one more idol. They then can have a service with them all singing and dancing and that's really great in their eyes. You don't really have to know the community to be the priest there, you have a role and you fulfill it, and if you go a bit extra that's nice, nice guy.
One point Chaim does have is that the Catholic church as excommunicated other evil members postmortem, and Hitler YS"V should be included in that.