See comments and further debate on following.
Falklands' Most Daring Raid - Falklands' Most Daring Raid - Channel 4
Sharkey's World: Black Buck - The Truth of the Matter
Where is Sharkey getting the information that Black Buck 2 bombs were unarmed? Is he mixing up Black Buck 7 mission?
Sharkey wrote
The raid on 3rd May was a failure, due to the fact that not only did the bombs miss the runway, but also because the Vulcan aircrew forgot to arm the bombs before releasing them
It is interesting that this especially significant fact has been omitted from several accounts of the ‘Black Buck’ raids.