In May police found two packages of cannabis when they searched Carson's house.
Defence lawyer Doug Taffs said Carson's sister wasn't the recipient of the cannabis. It was for his father, who shared her house.
Carson had been down there for a couple of months looking after his father who was in extreme pain, said Mr Taffs.
He knew his father had used cannabis for pain relief in the past so when he went back to Granity where cannabis was cheap and abundant, he sent some to his father.
"It was a misguided but compassionate act", and this was reflected in the very light charges the police had laid, Mr Taffs said.
Judge Somerville said Carson had four historic charges of the same nature, but he accepted in this case he was supplying his father for free with pain relief.
He convicted and discharged him and ordered him to pay court costs of $132.89 on each conviction.