Change of scenery and opportunity to win starting CB job. He could have come back and competed with Maxwell for the starting CB job but this also was his first chance to make a choice based on where he wanted to go. His career has been up and down due to injury and bad personal choices. I think this was the best move for him. Will give him a chance to show the NFL that his talents transcends any scheme. He is the more prototypical DB, with decent man skills and speed to play the various zone schemes along with press technique.
Side benefit, with him being in NY, I am sure his new fans could not care less where he went to college so he can openly root for his Ducks in peace.