Jon Cooper, a 62-year-old chiropractor, had attached a plow to his quad to clear the path outside his office in St. Albert, north of Edmonton, on Jan. 8, 2011.
He had been plowing the same walk, a route regularly used by seniors living in nearby complexes, for the past nine years.
He got stuck in the snow and his son Dan Cooper pulled up in his truck to help his father out.
RCMP got involved because using an ATV on a city street is prohibited. The situation escalated into a scuffle with the officers.
When it was over, the father was given a $250 fine and the son was charged with two counts of obstructing a peace officer. Those charges were also stayed in court earlier this week.
A spokeswoman with the justice department said it was not in the public's interest to continue the prosecution. RCMP did not return phone calls seeking comment.
Jon Cooper said Wednesday the family plans to file a lawsuit against the RCMP.
"They're trying to make amends, which is good. But it's too bad we had to go through what we had to go through."
He added the family has spent nearly $30,000 in court costs fighting the ticket and criminal charges.
Dan Cooper, also chiropractor who shares the same office with his father, said he feared losing his licence over the charges.
The 36-year-old said one of the officers threw him to the ground and he did nothing to provoke the attack.
He said the event should have unfolded differently.
"This whole thing should have come down to common sense," he said. "If (the officer) had used common sense, he would have put on his lights and helped us out."
His father said they have received messages of support from the community and from people around the world who've heard their story.
Jon Cooper said he plans to keep acting as a Good Samaritan, but won't be using his ATV to plow the sidewalk again.
And he said he doesn't have to. Since the incident, city crews have been clearing the route after each snowfall.
"I've gone out there to shovel it and it's always been done."
— By Chris Purdy in Edmonton