The SO is an experienced one
No doubt he is experienced - in the role of being an SO. One of the first things you figure out as a capt is how much you didn't know about the role of the capt when employed in a different seat. This SO is about to have a lesson on the subject.
CRM techniques also involve the FO/SO understanding the correct way to question instructions, which conflicts with Gen Y conditioning to cry like a baby when dissatisfied, ignored, not placated, etc. When combined with inexperience, brazeness and youthful ignorance plus the wrong capt on the receiving end, you get a cockpit "conflict".
At least it happened on the ground. Now the SO can stand up and account for his actions. He better have his poop in one sock or the list of management capts lining up to kick his arse will be long and distinguished. Just like Slider's johnson.
My money is on the capt.