French Connection, page-28

Simon's presence at some deal discussions would be valuable for added credibility and his commentry on the purchasers' ideas for their use of BRN's tech. With his reputation, he'd be viewed as a kind of independent adviser for both parties.
Sometimes his commentary would reduce the purchasers' expectations and there's nothing wrong with that honesty. Other times his commentary would raise the expectations, along with a bigger deal for BRN.

Of course he would have to state up front that he is a shareholder but not staff and that he is paid a fixed fee which is not a percentage of the deal.. It's all about transparency.