I’m pretty certain AFFSA, who wrote the reg, would say being at work is NOT rest. I’ve been at AFFSA meetings on this subject.
Short story, I was late coming off an EAL trip, called my guard unit’s guard shack and left a message that I would need to be off the early go; came in for the noon brief. Two hours later, I was in chute joining the Caterpiller Club. You just never know, best of all the board found no supervisory error to the relief on the new Wing King.
I’d follow crew rest rules scrupulously.
GF