Frankly, I’d get my paperwork together and get a free consultation with a suitable lawyer. I’d expect the lawyer to determine whether they thought I had a case, and explain why, before I’d hand over a penny. And then I’d get a second opinion from another lawyer. Chances are, it’s not worth suing.
This is kind of accurate. If they fired him with no reason given he wouldn’t have a case in terms of unfair dismissal. But if they fired him with cause for a poor performance he would have a case in that the basis for that dismissal was fraudulent reports originating in another store. And there is a clear motive and apparently a record of that.