A competitive line would be -6.5, not -6. I just do not get the rationale behind the 6, unless they are damm sure the Panthers are going to cover.
The best part about being a local book is setting a line that falls in with Vegas and usually watching the lambs come to slaughter. The vast majority of the time a local shades his line with the local team, not against, especially in big games. Most everyone loves to be a homer in a big games.
When locals start shading their lines against a local team they are taking on the risk of gambling. Not something a book should generally do. All of the sudden their thoughts and emotions are added into the equation, usually something the book does not have to worry about.
Anyway think the -6 in the New England area is a very interesting number.