Turns out that changed at some point. Now blocking someone also prevents them from replying directly to one of your posts. (They can still post in a topic you started.) The error message is oblique, and I don't remember seeing this feature announced, so it can be confusing.
And kids being kids. Plugging your ears against arguments. I can understand blocking people for various reasons. But blocking people you are having a discussion with, that is just lame and immature.
