Am I not right in thinking BA have responsibility for thie own security at T5 through G4S? So, whay don't BA have a staff comb that operate on a different basis?
The 100ml rule is ludicrous anyway because it would be easy for multiple amounts to be combined airside. I don't know if this is still possible as they have photo tracking now but, I used to occasionally use my airside pass to shop before a trip - leave my purchases landside then go back though security for duty. It was handy where electonic items were on special offer and I didn't want to cart them from pillar to post on a trip or rely on BAA's super efficient buy and collect service - don't know if this is still available either. Can't say whether I was breaking any rules or not and was never challenged - I once had the same conversation with the same security operative at LHR about 40 mins apart - it was spooky because she didn't initially remember me and told me all about someone else who had been saying exactly the same thing that very afternoon - me!