I was part of a clunky fund raising interview, at a radio station, once upon a time. Talking to the host before we went on the air, everything was cool. Good rapport, and comfort level. However, the headset I was given at the last minute wasn't working, so I didn't hear the first question, and asked the host to repeat the question. The request seemed to unnerve the host, and unfortunately, the rest of the interview felt uncomfortable.
And thank goodness the guy didn't go off like Cowherd!
My take is the Harbaugh interview went south after Harbaugh confused the context of "buy" with "bye." Simple mistake but, I think when things like that happen to certain egotistical radio hosts, they may feel like the audience is going to hear it like it's their (radio host's) fault, so they start acting-out, so to speak.
In any case, Harbaugh is likely to get more press out of this, than if it went well, which may have been his aim in the first place. Crazy like a fox? Or just crazy?