Diggs is a case of a guy who got his money and got lazy. I hate saying that, but it's flat out true. He was out of position ALL THE TIME. Magically, he wasn't before he got that new contract.
Everybody on the defense was out of position. The complete and total crap fest that the defense and its members became also coincided with Hurtt being appointed to lead it. I think that was more the cause of the disinterest in playing the game 150% as anything else.
Williams, Spoon, Brooks and Reed balled out. As did Bobby and guys like MJack who were fighting for roster spots. But the DB group slacked as a whole, likely because the system, going on three years, was ineffectively taught and executed. And Diggs, I'd venture, being a vet who knows something about scheme, became somewhat detached from things and his indifference probably infected guys like Woolen. Classic bad apple. But I don't think he's a bad character nor a washed up player. Just like many players under poor coaching, an experienced dude who got fed up and let his frustration show on the field.