STP,
No one is asking the security staff to turn a blind eye and let pilots go through with potential weapons.
But whatever happened to simply confiscating the item or even turning the chap back asking him to check it in? Does the police and sensationalist press really need to get involved?
Their jobs is to prevent any dangerous items from getting in the cabin, not to be imperious a$$holes about it.
It doesn't take many trips to LHR to understand that these idiots hate flight crews with a passion.