I wonder if they realise,the 100ml restriction doesnt apply to crew coming into the UK !
An interesting condundrum. If they arrive then presumably the threat level of the whatever liquid they are carrying has been judged safe - i.e the aircraft was not been destroyed on route and therefore the country of origin has been fully vindicated in allowing pax and crew to travel with liquids in containers of more than 100ml volume. Equally, it is most unlikley, having gone to the trouble of secreting liquid explosives on a flight from wherever, that they are actually destined for mainland UK.
If the flight doesn't arrive because some numpty has successfully used the lax security procedure to take on board liquid explosives in a container of more than 100ml then the above fact is somewhat irrelevant.
Incidentally, the deemed threat is from the container being greater than 100ml which is a joke as you can easily buy bottles of water ( and a host of bottles and containers) airside. It would only take a dozen or so mavericks acting together to accumulate 1lt of active chemical. Maybe this is the flaw in the system?
The process of screening liquids of up to 100ml is two fold. One the quantity in itself does not present a huge threat and puts the pax under 'stress' which is monitored and observed by staff. If there were multiple attempts to smuggele chemicals airside this would in all likliehood be thwarted in this way.
Seems to have worked so far - thankfully.