Ive listened to recording five times now and changed my mind.The "standby" at 0:24 is not Nigel taking the piss or playing for time.Hes getting the cabin ready call right then.He announces fullly ready at 0:35 and is given line-up clearance.He can now do the 4 item checklist as he lines up but...the ATCO comes back at him instead of letting him line up in peace(hes said hes ready).The ATCO then takes his second "standby"(bit sarcastic)to mean that he isnt actually ready when what hes trying to say is "Im taking the active rwy,let me do my checks".
My verdict:over-zealous ATCO with a touch too much sarcasm from old Nigel.But its still a storm in a teacup and not worthy of further consideration.