I'm a newbie of course but I've run my my fair share of video game leagues, fantasy leagues, and even NHL94, 95, and 96 leagues on genesis back in the day keeping all results on paper.
So.
There will always be trades that favor one team over another. Sometimes there are ripoffs. Ripoffs are more a problem in dynasty leagues. Everyone's fear here isn't the trade but that carse, being a good player, might now be REALLY good. The only fair way to do things is to have everyone vote and if 70% or more say to take it back, take it back. I've been the commish that has decided if trades are fair or not and its just too much power for one person, people end up feeling powerless in the process. I call for a vote on the Carse trade. At least 70% of the participants have to vote, and to have the trade overturned 70% of the votes registered must say so.