>The law clearly is on the side of rolling back the transactions
No it isn't, there's no precedent for this because it hasn't existed before. The nearest thing I can think of is when that fake letter was sent out about some company causing the stock to tank. Did all the people who bought the stock when it was low have their transactions rolled back? Because that's what happened here, someone used highly technical means to cause an artificial price dive and one guy was able to take advantage of it. It's not at all clear to me that he should give any of it back.
No it isn't, there's no precedent for this because it hasn't existed before. The nearest thing I can think of is when that fake letter was sent out about some company causing the stock to tank. Did all the people who bought the stock when it was low have their transactions rolled back? Because that's what happened here, someone used highly technical means to cause an artificial price dive and one guy was able to take advantage of it. It's not at all clear to me that he should give any of it back.