
But the Patriots aren't satisfied. They are now demanding that Branch pay the full amount of fines he accrued by not reporting to the team. Those fines exceed $600,000. This demand appears to be within the Patriots' rights, and the likely reason they hadn't already asked for them is that they didn't want to burn bridges with Branch while there remained a possibility of him returning. With him gone, however, those bridges are probably irreparably destroyed, so they might as well collect (although I suppose doing so could run the risk of upsetting some of Branch's former teammates, who seemed to love the guy). Even with Branch set to sign a 6-year, $39 million deal (including a $13 million signing bonus) with the Seahawks, $600,000 is an awful lot of money.
According to ESPN's Chris Mortensen, the Patriots are also preparing to file tampering charges against the New York Jets because the Jets, and specifically head coach Eric Mangini, told Branch what they had offered the Patriots as compensation for the wide receiver. The Boston Herald's John Tomase has the story:

The Patriots allowed Branch to negotiate with other teams during the last week of August. During that time, the sides were granted permission to discuss contract terms only. The Patriots contend the Jets told Branch about their offer of a second-round pick after putting together a six-year, $39 million contract.To add to the drama, the Patriots are playing the Jets this Sunday and 35-year-old Mangini--the NFL's youngest head coach--was the Patriots' defensive coordinator until this year. I wonder if Bill Belichick is simply trying to get into his former protégé's head as he prepares for this Sunday's game?
The Patriots believe that knowledge “poisoned the waters” and guaranteed Branch wouldn’t re-sign with the team.