Revman,
Sad to say, I saw a similar thing at LHR not long ago. Guy in the queue, has small bag and laptop in hand. Told quite firmly, that as he can only have one item of hand luggage, he must put the laptop into the bag. Expressing consternation, he did so, only to be told a few seconds later at the check point to take it out for screening. Doh!!
It really is very difficult to take these security people seriously.