Usually companies have a clause where they have the first right to buy the stock options back before you offer them for sale to anyone else. Employee stock options are sort of intended to be NODROP, and if they want to make shares available on like second market, they need to create a pool of shares specifically for that.
I would be curious about the legality of working around that restriction - like, what if the option holder creates a contract with someone who wants to buy the options, where they agree to hold onto them and then give them to the buyer once they are allowed to in return for a lump sum payment up front. Or, perhaps, they set up an agreement where they are given a lump sum payment up front, and agree to pay the buyer an amount equal to the current value of the stock once it becomes publicly available.
I've looked into exactly this arrangement before. I couldn't find anything definitive, but I imagine that the second buyer will be in a very risky situation should the shareholder decide to break the contract down the road.
Oh, so secondary markets are still beneficial to participate in if permitted. So this guy should participate if he can. But you work with the original company, etc., I suppose. Makes sense.