It’s a common myth that frogs will stay in boiling water if the water is heated slowly enough. They can sense heat and will most definitely attempt to escape.
You could just as easily have said, “Hey, I’m having a hard time trying to determine if you’re being sarcastic, could you please clarify?” and then waited for response to decide to include the bit about Nazis in you reply.
Oh, it’s not the first time I was thrown over a cliff, and it won’t be the last. What can I say? I’m a rebel.