The Patriots thought they knew what they were getting. Thomas thought he knew the situation he was entering.
Both sides miscalculated.
That's why, in my opinion, both sides share the accountability for this situation going downhill in a hurry.
It seems like yesterday that Thomas was smiling while walking around the locker room, passing out "Humble Pie" T-shirts to teammates as a sign of how he was embracing Bill Belichick's straight-forward, no-one-is-beyond-reproach style.
He was buying in at that point, in 2007, even though he wasn't playing his preferred position of outside linebacker. Thomas played every game that first season in New England, and the Patriots went 18-1, so it wasn't like he didn't make contributions. He was excellent in the Super Bowl loss to the Giants, which probably was his best game as a Patriot.
From this view, one of the key forks in the road for Thomas and the Patriots came as the locker room dynamic changed in 2009.
Thomas is a strong personality, someone who sometimes would point out the differences between the way his former team (the Baltimore Ravens) and the Patriots did things. When the Patriots had established veterans like Tedy Bruschi, Mike Vrabel, Junior Seau and Rosevelt Colvin in the linebacker room with him, it was a powerful force that, in some ways, kept him on course with the "Patriots Way" of business.
When that mix of linebackers was no longer together and it was a much younger group, Thomas' strong personality had more space to exert itself. Gone were the "Humble Pie" T-shirts, and in their place was a player who grew increasingly frustrated with his role and what he felt was a lack of communication -- and he didn't shy from expressing his feelings publicly. One could understand why Thomas was frustrated at times; after excelling in harassing quarterbacks with the Ravens, he was not used in that role very often with the Patriots and struggled to come to grips with why that was the case.
In the end, had Thomas known the distinct differences between the Patriots and Ravens, he wouldn't have signed his big contract in 2007 and instead would have joined his former Ravens coordinator Mike Nolan, who also had pursued him, in San Francisco.
Along those same lines, had the Patriots realized Thomas wasn't the complete package they thought he was for their program and system, they wouldn't have signed him to the franchise-record free-agent deal. A team that invests that much money needs to hit on a player who represents what they are about on the field and in the locker room.
Every year, the warning is sounded when free agency begins -- buyer beware.
The pairing between the Patriots and Thomas is the latest evidence of that.