Road Traffic Act 1988

4(1)Where a contravention of section [F115A,] 17 or 18(4) of this Act committed by a person in Scotland (referred to in this sub-paragraph as “the original offender”) was due to the act or default of any other person, being an act or default which took place in Scotland then, whether or not proceedings are taken against the original offender, that other person may be charged with and convicted of the contravention and shall be liable on conviction to the same punishment as might have been inflicted on the original offender if he had been convicted of the contravention.E+W+S

(2)Where a person (referred to in this sub-paragraph as “the accused") who is charged in Scotland with a contravention of section [F115A,] 17 or 18(4) of this Act proves to the satisfaction of the court—

(a)that he used all due diligence to secure that the provision in question was complied with, and

(b)that the contravention was due to the act or default of some other person,

the accused shall be acquitted of the contravention.