The phenomenon is "I believe X" and the reaction is "SO YOU DON'T BELIEVE Y."

Elsewhere people have reacted to a situation by saying "I believe this is okay, because free speech."

But those people didn't include this specific incident, so they apparently don't believe in this one.

The difference is a statement on waffles is not a statement on pancakes, but a statement on absolute free speech is a statement on all speech.

The first one is using a statement on an adjacent issue to demand attention on one’s own pet issue. The latter is calling out alleged hypocrisy.