A statement from the provincial Criminal Justice Branch says an altercation broke out between the unnamed driver and officers in a school parking lot early March 22, 2014.
When the driver was arrested and placed in the back of a police cruiser he lost consciousness and was taken to hospital, the statement said.
Crown counsel reviewed the file, including witness statements, police reports, photos and medical evidence, and determined there was no substantial likelihood of convicting the officers.
The statement said the officers' statements were "reasonably capable of belief," but the Crown had concerns with evidence given by the driver and female passenger.
The branch will only release limited information on the incident because the driver has been charged with assaulting a police officer.