"Evidence" might be too strong a word based on some fluff piece written by a local news station. I doubt half the money wagered will be on prop bets, maybe in Vegas. Maybe. I know a lot of locals that don't take them at all. Even at some offshore shops they take them but limit what you can bet. At several places I can only bet $100 max on props but can bet several times that on the side. And if this game lands on 3 (with Pats winning) then that will crush a lot of the books. They won't write a winner on the side, they will pay everyone that laid the 2.5, pay everyone that took the +3.5, push everyone else. You'd think if 50% of their action was props it wouldn't kill them but you would think wrong.