"This should not be taken as condoning impaired driving," Judge Paul Scovil wrote in his decision, released Monday. "Nor should the public think that the defence of necessity is an easy one to make out.
"Rare is the case that such evidence would be accepted, but this is such a case."
The 12-page decision said Roger Pleau was impaired when he drove his injured friend, Eldon Deegan, to hospital in Upper Nappan on Oct. 4, 2012.
The two men had been drinking beer when Deegan left his apartment to smoke a cigarette outside and fell down some stairs, cutting his head on an iron handrail. Both men were locked out of the building without a key and neither had a cellphone. The building also did not have a buzzer to alert any other tenants.
Scovil said Deegan was incoherent and having trouble breathing when Pleau "panicked" and drove his friend to hospital, where a nurse noticed he was intoxicated and called police.
In acquitting Pleau, Scovil said the accused was forthright and credible in his testimony, and truly believed his friend was going to die.
"His inability to call 911, the panic of being locked out of the apartment building with someone in obvious medical distress would lead the accused to take the action that he did," he wrote in his decision.
Scovil also said Pleau did not believe he had time to find a reasonable alternative to driving, given his friend's serious injuries.
"Given the time pressures of the situation and his lack of medical background to assess the situation, Mr. Pleau would have felt he had no other legal alternative other than to transport his friend to the hospital," he wrote.
Finally, Scovil said he had to consider the proportionality between the harm inflicted in the case and the harm avoided.
"Were Mr. Deegan to suffer irreparable harm as a result of delay in obtaining medical attention, it would surely outweigh the harm brought on in this case of the impaired driving."