A government chauffeur has won her battle for workers' compensation after hurting her shoulder while carrying heavy bags for former defence minister Stephen Smith while he sat in the car.

Canberra Comcar driver Lynette Prater suffered a long-term shoulder injury from lugging the eight bags two years ago, but workers' compensation authority Comcare refused to pay.

The part-time driver had to take her fight to the Administrative Appeals Tribunal to win the right to have her medical expenses and lost wages covered.

Mr Smith said he had no memory of the event but he or his staff would usually offer to help carry their bags and heavy document cases.

The then 49-year-old Comcar driver picked up the minister at Canberra's RAAF Fairbairn airfield late on November 20, 2011.

Ms Prater's official incident report says: ''Mr Smith came out and had two small silver cases with him. I then went to pick up the cases. They were extremely heavy and I could only manage to take one up to the car. He said he had a few more cases.

''Mr Smith put something else in the boot and then went and sat in the car, whilst I loaded the remaining cases in the boot.''

When they arrived at Parliament House, Ms Prater was left to unload the cases from the vehicle.

''Arriving at the basement, Mr Smith went and got a trolley for him to take the cases inside and left me to take them out of the boot unassisted.

''Left arm a bit tingly. I put this down to being a sore muscle.''

She told Fairfax Media she accepted the task when it became clear she was expected to lift the minister's bags on her own.

''I just shrugged my shoulders and thought, 'Oh well, I'm going to have to do it,''' she said.

The driver said she hoped the severe pain in her shoulder would go away, but when she was diagnosed with a muscle tendon sprain, she wanted workers' compensation.

Her claim was denied by Comcare, which cited the delay between getting the injury and lodging the claim.

But after hearing the evidence, the tribunal found this week there was no other likely cause for Ms Prater's injuries and the driver had done the right thing by waiting to see if her pain would settle down before seeking help.

Comcare was ordered to reverse its decision and accept liability for the injury.