I don't watch the NBA so it's not something I can even speculate on.
With regards to football, the only place I could see it possibly happening is the bottleneck of officiating.
But, even then, the 'evidence' is not even close to supporting the concept of true scripting, meaning the NFL has per-determined outcomes.
We can clearly see players making plays and often teams just beat other teams in spite of bad calls.
Maybe there is some favoritism. It's clear that some QBs get better calls and protection from refs than others. If that is on purpose or not is anyone's guess, but as it pertains to actually scripting outcomes is not supported by a conclusive body of evidence.
What the NFL wants is money, and that revenue is driven by TV ratings. And since ratings are based on what the public wants to see, I can see the potential for the NFL to want its star QBs to win more than lose and even want those stars in the postseason. So in that regard, there is the potential for officiating to influence games in favor of those star players.
Gambling is the aspect that is going to really shed light on this stuff, because U.S. Congress is eventually going to get involved. The potential for gambling to influence the game is there, which is why the NFL avoided it for decades.
But there are too many eyes on the games and too many players/coaches/owners involved to believe in scripted outcomes without there being even one whistleblower by this point. JMO