You're right. It was an unproductive method of describing the behavior I was seeing (and was too easy to interpret as saying the person is schizophrenic rather than exhibiting behavior I associate with schizophrenia). It was also insensitive to schizophrenics.

In my defense, schizophrenia runs in my family, and I'm very familiar with it...I don't think of it as an insult. But that's a local custom in my family that I shouldn't think follows in the rest of the world.

When describing behavior and not as a slur I don't see any problem.