He never should have been the pick in the first place. The Phins were desperate for a WR and Nicks was sitting there. Every team in the NFL is desperate for pass-rushers and Clay Matthews was sitting there. This isn't hindsight either - plenty of people wanted the Dolphins to draft Matthews or Nicks in the run-up to that draft - it was a surprise that both were available at the time.
Fact is, the front office out-smarted themselves again by picking Vontae Davis. There were rumors of "character concerns" with Vontae. Maybe unfounded. Either way, this front office thought we're going to prove they could take a guy that slipped because of character concerns and "coach him up" and turn him into a player. It was a bonus to them that his brother played in the NFL, and knew the ropes (sound familiar?).
Another front office failure.