Oddly enough, several professional sports gamblers were aware of a NBA referee manipulating game from their data analysis, well before the NBA became aware of it.
That was probably 10+ years ago and I suspect data analysis by the leagues is much stronger now. Still an insane line that needs to be walked between the leagues getting revenue from the sportsbooks and gambling not impacting that play.
Tim Donaghy (ref): https://en.m.wikipedia.org/wiki/Tim_Donaghy