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?
It must be said - bitch all you want about the claim that these guys manufactured Arduino, but on nuance, it appears supportable. When team members who built something (or worked on it to a significant extent) move on, the work they did previously is in their portfolio whether you like it or not. This practice is standard in other industries, too, especially marketing. And of course, the obvious: if, as is claimed in the post, Arduino is afraid of damage to the brand, why not complain about all the other BLAHduinos out there?
This makes Arduino look bad, and if the founders of the contentious project are actually shady, they are loving the cred this reaction will earn them.