I would guess the first power down and reboot didn't work so they tried it again, and again. With a limited number of options, spare parts and with a crew approaching their time on duty limits they probably did multiple resets, box swaps and various other trouble shooting tasks in vain. They may have even fixed the snag but not before the crew went out of hours.
It's frustrating as hell for all concerned but as safety is the priority, getting it right is paramount.