Wow, that sucks. I did notice in my tournament tracking for my fellowship, that the points went with the person if they left, but it never happened before the rewards were distributed. It would be nice if, once you got the 10 chests, it became locked in. In other words, rather than use your ending point total (or the total when the rewards are distributed), they used your highest point total during the tournament. Since if you join a fellowship after the beginning of a tournament and your points don't count, why should they not count if you leave after the tournament is over? There is no need to remove those points if somebody leaves since they can't contribute those points to a different fellowship and they were earned while in the fellowship when they earned them. So I vote for "high point" rather than "end point," as the criteria for tournament chests.
AJ