Fantasy settings ( lock bench players) mistake by Commissioner

I’m the commissioner in a H2H Yahoo league and I mistakenly thought my previous years settings would remain the same and I didn’t check each setting thoroughly. I realized that the setting to lock the bench players was turned off when one of the managers made a move on Monday at 4:00 pm PST and picked up Jordan Mason because McCaffrey was declared out for the game. He used a player from his bench to do this (DeAndre Hopkins) and that player had already played the day before. By the time I realized what had happened the game had begun, so I felt that I had to honor the move because it was only allowed through my egregious error. I called both managers and told them my decision and sent out an email to the league as well. Of course my decision allowed the team that picked up Mason to come back and win the matchup. I have since made the change to lock the bench players after their game has begun, otherwise it will be a free for all on picking up players for the rest of the year. Should I have banned the move?