Very wrong. He might have to serve some off season time, but it will be very short. This is his first DUI in the NFL. His last was over 6 years ago while a teenager in college. (common mistake btw). He WILL be suspended however, but his time will be in the 2-4 game range.
Back to the OP -
If he's smart he'll be back with the Pats. All he has to do is look at the financial success players who have played well with the Pats have gotten. One, even just decent year with the Pats will almost completely rehabilitate his rep. If he thrives then the sky's the limit.
Given the likely suspension, I think an offer of a one year prove it deal, that would consist of a Million guaranteed, and incentives up to $5MM if he thrives, less he's just decent. The Pats can easily fit that in their cap (and a bit more if necessary).
His alternative is to go make marginally more somewhere else and hope for the best. That is why I think he's back. IF he is just about the money, then where else is he more likely to have the success he needs to get, than right here...even if his numbers would suffer because there is no #1 in this system