I vote that Spaceheater should be able to join the conference call. He has a lot of experience with start up companies and knows the market.
Not only are he and Petar familiar with each other, but spaceheater would be an asset to Petar as an advisor.
Plus it would level out the playing field. Spaceheater would not easily be fooled. And if he came back from the call and reported confidently, I would feel better about it.