I'm sure Danny did his due diligence and shopped Gauthier to every GM in the League. The problem lies in the old boys GM network...these guys all talk, and with each call he exposes his position of weakness.
Thus, opposing GMs smell blood in the water and the offers go down, despite the obvious elite skill of the player being shopped. Throw in how unprofessional Gauthier and his reps looked giving the Flyers the cold shoulder, this could have given other GMs pause for thought also.
In the end, Danny did his best from an obvious position of weakness. He simply had to accept a few warts for a top 10 prospect....in this case, the warts include size and injury concerns.