If you saw the way BA copilots are trained,
Oh please, fetch me a bucket!.
You didn't answer the question, is the Captain relieved of responsibility for the RTO manoeuvre or is he expected to confirm the decision before the FO closes the thrust levers and starts the reject?. If the former, how does that fit in with the ANO and the Commanders legal responsibilities and if the latter why bother having the FO do it in the first place.