I mean sure, in all honesty, everything is probably on the up and up, and it all comes down to coincidence. I don't think it takes a lot to swing games. Has it ever happened, who the hell knows.
Would I be shocked to find out that the NFL has "areas of emphasis" for the referees going into games and those can swing outcomes, nope. Would I be shocked if there was an outright Tim Donaghy situation, also nope. At the end of the day, its all entertainment and thinking poo has WWE level scripting helps with the coping the shitty games happen.