He had Talent ,,,I'm thinking two possibilities.

One he did not push himself hard enough this camp .
Two he didn't engender himself very well with Brockers , Donald , Ebucan , Matthews , Wade or Joe Barry to get some mentoring on how he could improve.
If either or both were real problems it would be fairly fatal . He would be regressing without having a good understanding of how poorly he was doing .
Unless he was flat out getting his butt kicked in practice by Edwards or Havenstien of course . If that was the case he should have known he had to get fired up and make some winning plays .
If he couldn't show effort and win then yes others looking good makes him look bad but there's likely reasons why he didn't perceive it or didn't show more effort . Maybe he simply thought he had a spot in the bag ?.
He'll check himself next time but if they let him go without ever getting in his ear to wake him up a little I think the organisation takes part blame for his failure to achieve at ahigh enough level.