In England, if you are involved in a car accident that wasn't your fault after having drunk a small amount of

alcohol (e.g half a pint of cider- below the legal limit), will the law and insurance companies nonetheless hold you more responsible than if you were sober?

No, you were under the legal limit that's what the breathalyser is there for.
It shouldn't even have to be revealed to the insurance company as you are allowed a certain limit anyway.

if you dont fail the the roadside test you are sober so the question is rather silly you cannot be drunk if you pass the test
at the side of the road.
AND if you pass the road side test the insurance company will never know you have had one. the police wont be bothered because you are legally fit to drive.
so nobody can hold you responsible at all
as stated the question is silly to any person with one ounce of brain

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