While Kyle Dubas was general manager of the Toronto Maple Leafs many players came through the system. Several have gone on to prove the team wrong for trading or not re-signing them, making Dubas look bad.
Perhaps one of the most surprising former Leafs to be having a great season is Kings forward Trevor Moore. The Leafs traded him after he didn't put up good results with the team in a relatively limited role. He developed into a serious depth contributor for the Kings over the past few seasons, but this year he's taken another big step forward as he leads the team in goals.
If Kyle Dubas had let some of these players stay, the Leafs could be in a very different position today. Hopefully, he does not lead the Penguins down the same path.