I got the sense that the employee was being paid for the 3 months, and spending time mostly to look for a new job -- not to do actual work for the company.

As a result, the CEO probably thought it was reasonable to ask him to help out with an emergency. Although it was after hours, it was hardly "overtime" in the sense of being hour 41+ of work he did for the company. Probably more like hour 2+, in her mind.

I'm not saying her expectation was realistic, I just don't think it was a "caricature". I suppose I think you're not understanding her point of view, much as she didn't understand the employee's point of view.