Incorrect.
http://metro.co.uk/2018/03/22/policeman-poisoned-salisbury-spy-attack-released-hospital-7409377/
Nick Bailey was the first policeman poisoned. He was poisoned at the park bench where the 2 Skripals were passed out.
Read the link. It’s the opening sentence.
Det Sgt Bailey was one of the first police officers to attend the house in a cul-de-sac a few hours after Col Skripal and his daughter Yulia collapsed in Salisbury town centre.
The admission he was made ill at the house was made by Lord Blair, the former Metropolitan Police Commissioner, in a BBC interview.
Russian spy may have been poisoned at home, police believe, as military deployed to Salisbury
I guess you'll have to argue with Lord Blair about the discrepancy.
In any case many police and bystanders came in contact with the Skripals that day and none of them got sick.