1. When you're wearing clothing supplied to you by the University and you're speaking from the football field, you're representing the University. It's clear from the guy's official NU football bio that he has specifically and deliberately used his position as a running backs coach to trumpet his Christian organization. Indeed, he casts what he does as taking "courageous" stands in the public square. I would argue that a kid who comes out as gay on the NU campus, represented as it is by Brown who emboldens himself by saying he speaks for Jesus, is far more courageous.
2. When you start to get rid of people because of what they say on a college campus, a chilling effect occurs and that's no good for intellectual inquiry (to the degree that even happens at an institution like Nebraska, not exactly the bright, shining light of the Big Ten). This guy needs to understand that it's not right to use his taxpayer-financed job to preach the gospel, particularly when it's so focused on scorn for some already-marginalized students. A public warning is the first step. My guess is that's not going to have any effect and he's still going to make his YouTube videos from the field in his NU togs and, at that point, he's fired for not heeding the warning.