When both parties have an Ontario Automobile Insurance policy, the DCPD applies. You recover from your insurance company, you have no right to sue to recover, and your insurer cannot subrogate to the other company.
As you are 100% not at fault, you recover under DCPD. The other party would only be covered if they have collision. A 50%/50% fault determination would result in you getting 50% costs from DCPD and 50% from your collision coverage (if any) and the same for the other party.
This went into place in the 90's. I believe it makes the insurance companies more picky on their clients as they will have to pay out and as you say 'it may not wash out'. Serves us right for voting the NDP in back then.
http://www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_90i08_e.htm#BK277
Ontario Insurance Act
Direct Compensation — Property Damage
263.
(2) ...an insured is entitled to recover for the damages to the insured’s automobile and its contents and for loss of use from the insured’s insurer under the coverage described in subsection 239 (1) as though the insured were a third party.
(5) (a) an insured has no right of action against any person involved in the incident other than the insured’s insurer for damages to the insured’s automobile or its contents or for loss of use;
(b) an insurer, except as permitted by the regulations, has no right of indemnification from or subrogation against any person for payments made to its insured under this section.