In 2003 (yeah, I know it is a long time ago), the Patriots lost to the Bills 31-0 week one. The Pats went onto a 14-2 season and a Super Bowl win. The Bills won 5 more games all year. People around the league were literally talking about the Patriots being one hit wonders and the Bills being the new powerhouses in the AFC and questioning whether the Pats should have traded Brady instead of Bledsoe.
There are always aberrations in week one. By all accounts, the Patriots didn't go as hard as they had in the past during the preseason. Vrabel seems to have the philosophy of treating the first month of the season as an extension of the preseason and historically as head coach has a really bad losing record the first week of the season. Even seasons where he won his division, he lost week one.
Every year, I discount what happens in week one. It really means nothing other than the W/L in the standings. That is why Belichick always said you never what type of team you have until at least week 5.