Were they being inflamed to potential violence? Or were they being bad sports and harrassing BYU fans and players?

Sure - there were a couple dozen fans around Dillingham who heard him yelling. How much do you think they were inflamed as a result?

I've seen the video - the Jomboy clip does a great job of showing the fallout of Dillingham inflaming fans. Dillingham turns to walk away from the refs and has a grinning fan in his face taking a selfie while saying "I love you coach!". Clearly about to go hurt someone.

Look - no one is saying Dillingham's behavior was awesome and all coaches should act like that. But it's a bit hyperbolic to claim that he was inflaming fans and nearly caused some kind of riot. 95%+ of the fans on the field had no idea he was talking to the refs, what they were talking about, or even that he was upset.