I can make my post a pretty lengthy post because I have a lot of inside knowledge and experience with this. I'll try to keep it short.
Colorado game had Big 12 officials, not BIG officials.
I will say, there isn't an overall conspiracy or hate against Nebraska by the BIG. Conference wide and even across college football, both small college and major D1, and into high school and youth football ranks the reason for poor officiating is experience. I know and have worked with several BIG officials. There are extremely good officials and what I'd call pretty poor officials in college right now.
The biggest issue is experience, we're seeing younger and less experienced officials in college. My generation (40-50 y/o) doesn't have a large number of officials on any level and that starts in high school all the way up to college. This age range you'd see 15+ years of officiating experience, with probably 10+ of college, if they pursued it. There was an official, who did Nebraska spring game, who had 1-2 years of college experience. This guy struggled and I mentioned to my dad I would have him spotting the ball on my high school crew. He's hired in the BIG this year. Overall, newly hired major D1 officials have very little college experience.
I'll skip mostly over DEI hiring, but this goes with the experience category. There was a major push to get female and black officials across D1, which caused fast tracking of officials through lower college and lower D1 conferences to get them into the major conferences. Some with less than 5 years total offiicating experience from high school to college.
It took me around 2-3 years of Class A to feel comfortable with NAIA. It took me several years of NAIA and a couple years of Nebraska practices and scrimmages to feel comfortable with Nebraska's 1's scrimmages. That was without the pressures of crowds, crowd noise, TV, media, grading, and games on the line. I think it was around years 8-9 of officiating that I finally was comfortable with the speed and complexity of a Nebraska scrimmage.
The crews Nebraska has been assigned to the in the past several years were lower ranking BIG crews. Crews are assigned by games with a regional thought in mind. Major games with ranked teams will get the #1 or #2, maybe #3 crew regardless of region. Games like Nebraska vs Purdoodoo will get a crew from the region that is in the lower half of the conference.
A final thing is what conferences are focusing on for the year. BIG and NCAA is focusing on Offensive Pass Interference this year. With that officials are seeking this out more and with inexperienced, lower ranked officials, they'll incorrectly call this because they haven't seen it before.
From field level the game looks entirely different than TV angles. Without talking to the official who threw Fidone's OPI, I know what he saw, the "belt" is his key (LOS to 10 yards downfield), he came to this action late, and saw a displaced defender and Fidone turned sideways, his assumption that it was a foul. Inexperience, pressure of not missing an OPI contributed to this. He probably errors more on the side of not wanting a missed call and will take an incorrect call when graded, especially since the focus is OPI.
There will be bias against certain coaches and official's thresholds will be lower vs those teams. I'll admit there are coaches that walking into the game we knew were going to be a headache and bitch nonstop. I've thrown flags against their team I likely wouldn't have thrown in a different game. Same is true with coaches that are the best to work with and enjoyable. They'll get those 50/50 calls.