If the law requires a commander to take certain actions before flight it is common sense to interpret there must be a designated commander before these actions can be taken!
On the contrary, I think "the person who is for the time being the pilot in command of the aircraft" means that the ANO clearly anticipates a situation where the commander is not designated before flight and, moreover, may change during the course of the flight. If two pilots, both qualified to be in command of the aircraft, split the pre-flight actions between them, who is commander? On a private flight, a tech log is not required and even a formal tech log does not necessarily require a pre-flight signature.
I think that any instructor on a check flight who claimed not to be pilot in command could easily find the AAIB making the same points.
I couldn't agree more. All I'm doing is pointing out the weakness in the current drafting of the law.