Certainly, Wills would not have “spearheaded” the operation. But a co-pilot is a vital part of the operating crew and indeed, the co-pilot is as likely to be doing the actual handling of the aircraft as often as does the captain – that’s the way to gain experience. (I write as a retired professional pilot with some 40 years total split between the RAF and airline flying). I know very little about helicopters, but an aircraft like the Sea King would certainly require two pilots to operate it efficiently. Airliners require two pilots and if one becomes incapacitated or ill, then while the remaining pilot can indeed get the aircraft back down safely on his/her own, this would be considered an emergency.Now when is a co-pilot anything more than just a co-pilot?
So not "just a co-pilot” but a vital part of a team, albeit not the one making the big decisions.
Jack