Last night I spoke with a friend and reader who enjoyed my recent Ethicist post, and not having anything else I wanted to get off my chest today, I'm writing another one. It follows the same format as the last one, wherein I quote the advice-seeker's question and then provide my answer (which differs from Cohen's, that's why I'm choosing to answer this particular question as opposed to others), without quoting his answer.
I am a prosecutor. As part of any case, we demand that the defendant pay restitution to the victim. Recently a disgruntled employee stole instant-lottery games from her employer, a local grocery store, and a few of those tickets were winners. She must repay the grocer the face value of the stolen tickets. But who should get her winnings? The defendant? The state lottery system? The person who bought the first tickets after the theft (who buys only winning lottery tickets)? — ANDREW BONAVIA, ITHACA, N.Y.
Me: Mr. Bonavia asks a difficult question; there is going to be a windfall gain for someone. There's also a fact question of whether the disgruntled employee knew the tickets were winners before stealing them (I do know that it used to be, a little less than a decade ago, possible for employees to determine whether some tickets were winners by scanning their bar codes, I don't know if this has changed). If the employee did know they were winners, obviously she can't keep the winnings, that would create a perverse incentive to steal tickets and then pay the face value of them, though other penalties for theft may offset the incentive, depending on the size of the winnings and the size of the penalty. But then it turns out that perverse incentive exists whether or not the employee knew, so it can't be right idea to allocate the winnings to her.

But it's also an unfair gain to the State of New York if they don't have to pay the winnings to someone. The state creates a certain number of winning tickets and the lottery business model assumes they will be paid out, it's an unfair gain to the state if they don't have to pay just because the tickets were stolen from the store.

There's no similar unfairness in allocating the gain to the grocery store owner, but there's also no justification for it, she's already been returned to where she was in the status quo before the theft.

So there's a problem with the money going to anyone, because it's a windfall gain. The way to deal with this is basically to create a state fund which provides relief to people who suffer windfall losses, and have the money delivered to them, but creating such a fund probably isn't an option for this advice-seeking prosecutor. As a second best option, demand that the thief give the money to the New York State crime victim's compensation fund. Crime victims have, in many cases, suffered a windfall loss.

Also, I'm not sure whether this really is an ethical dilemma for the Prosecutor, because even if he made a very poor choice as to how to deal with the winnings, it would be strange to criticize that choice as unethical. Unless he took the money himself, but that's not the topic being discussed.