We gave up two 2nd round draft picks for Brandon Marshall. He has enormous talent but the issue was his behavior off the field. He has a long history of bashing women, going back to his college days at Central Florida. It was subsequently identified that he has a borderline personality disorder. This is a very serious mental health condition in which he just fixates on himself and is extremely difficult to live with. In one incident he was stabbed by his wife while in Miami.
Since leaving the Dolphins and going to the Bears, he has been a model citizen. His QB, Cutler has been very supportive and they appear to combine well. Denver and Miami couldn't manage him and he was a danger to himself and his wife, but in Chicago there are reports that he has made progress with his condition.
The interesting thing is that Ireland kept on recruiting and drafting players with fairly big mental health issues. Brandon Marshall, Davone Bess, Richie Incognito, Jonathan Martin all had serious mental health issues. There may be others. Some might say that this was Jeff's blind spot. I would argue that they were not properly evaluated and this was a major deficiency of the Dolphin evaluation process.