"He actually did the smart move by selling when he did as the stock price has moved about 20% lower."

but why didn't he sell it all? why does he now have 25k more than he did before?

you don't know the reasons he may have had to sell what he did. the old saying goes that there are many reasons to sell, and only one reason to buy. it could have been for the simple reason that he needed the money. you simply don't know. but you act as though you do.