And how did the perpetrators carry the nerve agent and smear it on the car door handle without dying immediately themselves?

in a glass capsule fired at a distance from an umbrella-like air-gun?
Firearm not contaminated, safe to remove to a safe location and dispose of it. Porton Down probably know, but aren't saying. With Georgi Markov it was a minicule hollow metal pellet filled with sarin fired or jabbed from a brolly. You don't need much (a raindrop would kill a big room) - that's the point of nerve agents.

we're being manipulated and May is letting the hysterical gutter press whip up anti-Russia passion.

The Falklands never did any harm to Maggie - just saying.
Now where can I buy a tin hat & air-raid shelter?