Fields was stuck behind another player. Gilman was trapped by the change in rules. Both want a chance to play in the pros. Their existing school situations limited that.
But Gilman in fact had a more "legitimate" reason to transfer than Fields did. The negative impact of Gilman staying was much greater than Fields staying since Fields likely would have gotten a chance to play while Gilman's chance to play pro football would have been severely impacted by having to wait for 3-5 years (not sure the commitment level) to do that.
I guess it is okay with the NCAA to accept a superficial lie and also okay for the Navy to change it's rules after the fact.