I'm a backer of the project and have been following it closely. You don't seem to want to get to the bottom of this so much as yell from a soapbox. Calling a guy and asking 'have you ever heard of this guy?' isn't really enough research for the accusation you made.
When you found out that he does have people on his team who were on the Arduino manufacturing team you still call him a liar. When he claims to have order invoices from your company and asks for your permission to make them public, he hears nothing.
There's a bit more nuance here than you presented, so how about you two get in to a substantive discussion before you hurl any more volleys over the wall at a guy who, though you disagree with, is making a quality product advancing your platform, and who has been trying to talk to you about this?