Hmmm...The evidence is: he's made one sale. Any person can talk the talk. He's clearly doing things a salesperson shouldn't be. You, a non-salesperson know this. But perhaps he will shine through when the product is released. But to iterate, thus far, he has made one sale, that doesn't make you a salesperson. Yet.

He may be showing people the code because he's proud of it...

Speak to him.