Are you this antagonistic face-to-face? If so, is it really productive, or do most people just dismiss you? If not, why do you think it's acceptable here? Because you can be anonymous?
The absence of that fact in the article does not constitute proof that it didn't happen.
Nor does it constitute proof that it did. You really have to learn that you can't have it both ways.
It depends on the evidence from the ex-employee which prompted the investigation in the first place. We simply don't know the content of that evidence. And speculating on it is useless.
The owner claims it was an anonymous call by someone who claimed to be an ex-employee. If that's true, I really do wonder about the quality of the evidence.
Wouldn't work. You'd be in no position to know that the competitor was using illegal software.
You missed this part:
If I can convince them I'm an employee (or ex-employee), I can shut my competitor down.