Well I'm not sure how someone would be able to without Tony's knowing but if that is the case THATS A HUGE DEAL and while I'm not one for ratting anyone out something like this if it's true should be brought to Tony's attention ( by whomever this was done to ) because as one of the top cue makers in the world his reputation could be seriously and permanently damaged.
How do you figure this could hurt Tony's reputation? From the information posted so far he is not claiming that Tony did any of the work. In fact he is making it real clear that it is only his work and apparently Tony doesn't even know about it. He is not trying to sell them or pass them off as Black Boar cues. He is selling them as his own Bernie cues made with the experience that he gained from working in Tony's shop. You know, the exact same thing that literally half the other cue makers in the world do which is to try to pump up their credibility by making it known that they got their experience from working in so and so cue makers shop.
Now if we find out he is putting the Black Boar logo on these cues (which we have no reason to believe at this moment) then that would be an entirely different story and then it could affect Tony's reputation. Now what you can argue is that Tony should be made aware because this guy may potentially be stealing some of Tony's customers which is an obvious no no for an employee to do to an employer. You can argue that Tony should be made aware if this guy was using his work equipment (Tony's equipment) for his own personal uses which would also be an obvious no no for an employee to do an employer (although we don't even know if he is using Tony's equipment at this point, maybe he is making them at his own house with his own equipment). You can argue Tony should be made aware because maybe this guy is using some of Tony's materials such as wood and glue and pins etc which would be theft (but again we don't even know this is happening). Tony's reputation however isn't at stake based on what we know. You have the wrong worries in mind.