I mean, a poor facility with words coupled with a lack of understanding of autism and ADD and lots of unexamined biases toward people with disabilities. The poor facility part is just to explain why she didn't get that comparing people with disabilities to people whose behavior you are criticizing means you're criticizing the people with disabilities. Faulty--logical reasoning? Use of analogy? Something like that.

Did you know sometimes I get hung up on figuring out how people think? I have a coworker whose linguistic glitches were a source of fascination, like, "how did she get there?"

...and in this case I don't think it makes a difference. It's not making a mistake that's a problem, it's being an asshole after it's pointed out.