From my perspective there's nothing wrong with firing a staff member over the phone when the good of the business rides in the balance, friendship or not. How do we know that Riley didn't tell Banker over the phone that he wished he could have done this in person, but seeing how Banker was on vacation and wasn't due back in Lincoln for days, it just wasn't in the cards. Banker has been in coaching long enough to know how decisions oftentimes come down the pipe at a moments notice.
He's obviously just a bit butt-hurt over getting canned.
When you are running a business, the business side needs to come first. Friendships are secondary.
My gut tells me Banker had to have known he was on thin ice with no mention of his contract being renewed at the last staff meeting that he just attended. After ranking near dead last in defense a year ago, and then having your system falling flat on it's face the last few game of 2016, anyone with half a brain would have to be worrying about their future.
Banker got plenty of bonus years with Riley the way it was. His defense was horrid at OSU.
He's lucky Riley gave him a nearly one million dollar payday by bringing him to NU for 2 years in the first place.