[ought-six]

By law, they can't say anything negative. When tehy don't say anything except to confirm that he did, indeed, work there, that is an implicit negative.

That's not true. It is not illegal to say anything negative or positive. An employer can be sued civilly for a negative reference, and for a positive reference, as well. Employers have been told by their legal departments to limit any references contact to the very basics: confirm employment, the dates, the position, and the salary.

[massgopguy]

I believe you can say “fired for cause”.