The evidence just keeps piling up, week after week. I'm not sure if they're necessarily in league with the casinos, but they do certainly favor certain teams they want to push over others. As a fan of a big rival of one such team, it frustrates me to no end. Everyone else in our division hates them with a passion because we all know they get preferential treatment by the refs and we've all been screwed by it many times more than they've been screwed by the refs, and the few times they have bad calls go against them, it's treated like a serious crime, while when we're screwed by refs it's just "oops, sorry".

I don't think the NFL nor the casinos have any incentive to fix matches. Isn't it pretty much the opposite? If there's an impression that the matches are rigged, wouldn't that deter betting?

I just think it comes from a lack of accountability at the officiating level. There basically aren't any consequences for even flagrantly blown calls, and the Replacement Refs fiasco made it a lot harder to try and enforce any. After the NFL tried to introduce video reviews of PI after the Saints-Rams NFCCG incident, the refs basically went into open revolt and refused to overturn just about anything challenged by the rule, and the NFL ended up backing down.

IMO the best move would be the NFL offering the refs union a pay raise too big to ignore, in exchange for agreeing to a meaningful system of accountability around flagrant and/or repeated blown calls. I don't know exactly what such a system would look like, and it'd be a hard balance to strike (people are human and sometimes just don't see stuff), but I feel like it has to be possible to some degree.

If they were actually in league with the casinos, they would never admit the calls were wrong.

They were favored against the lions, but it definitely didn't change the outcome.