I re-read this, not to fire back but to understand how you arrive at your conclusion. I think you are interpreting (or assuming maybe), from when I asked about his employer, that I suspected he stole the parts from his employer. That's not the case at all. I just needed a pressure point.
From a legal standpoint blackmail requires the "receipt of money or valuable thing". Because the thing being received is an even exchange of goods already agreed to by both parties, and the threat on not receiving is not an illegal action in itself, it is not likely or plausibly blackmail.
