Radar Identified is correct. Section 199 of the HTA required the driver to report the accident to police. He was driving on a highway. Your son was not and had no obligation to report.
Like "shall" and "may," the courts have also ruled that the word "and" and "or" have meaning. In short, the word "and" means both. This and that. The word "or" means one or the other. This or that. Section 258.1(1) uses the word "or."
This means he was required by law to report the accident to his insurer if he's involved in an accident ... or ... if he makes a claim under the policy for damages. He was required by law to report within 7 days. The Act provides him only one excuse not to report within 7 days; he must be incapacitated. He was not incapacitated and thus violated the Insurance Act.
The Insurance company was required by law to invesitgate the accident and this required them to speak to your son. They never did so. They either were not told about the accident or failed to conduct a proper investigation.
Insurance Act
Notice of accident
258.1 (1) If an automobile insured under a contract is involved in an incident that is required to be reported to the police under the Highway Traffic Act ... or ... in respect of which the insured intends to make a claim under the contract, the insured shall give the insurer written notice of the incident, with all available particulars.
Same
(2) Subject to subsection (3), the notice required by subsection (1) shall be given to the insurer within seven days of the incident.
Same
(3) If the insured is unable because of incapacity to comply with subsection (1) within seven days of the incident, the insured shall comply as soon as possible thereafter.
REGULATION 668
2. (1) An insurer shall determine the degree of fault of its insured for loss ... or ... damage arising directly or indirectly from the use or operation of an automobile in accordance with these rules.