Ontario Highway Traffic Act

Ok everyone, 2 days ago i have received a ticket from an officer. speeding 21Km/h over on a 40Km/h zone.
This place is right beside my house, my dad was not feeling well at home. he is a senior 68 years old with Alzheimer disease.
He gave me a call, so I had to rush and get him checked up before any major thing happen.
Could that be a defence for ...