The speaker had a proven track record building models adjacent to the sports betting world primarily in baseball but also covering basketball and football. They did in-depth work exploring the impact of different officiating crews on outcomes and found it added no additional predictive power. The implication being that there is no evidence of officiating bias across sports. The exception was baseball. Definitely an effect in baseball.

I haven't seen the research myself, but trust the source. I've never been an officiating conspiracy theorist, but this definitely reinforced my prior that refs in general are trying to do their job honestly, it's just that some of them aren't that good at their job. Especially at the collegiate level.