I refer to this original post:

http://www.ontariohighwaytrafficact.com/topic497.html

The car driver, decided to pursue him in his car until he drove in front of him and cut him off on another driveway which is a potentially dangerous behavior that could have resulted in another collision and injury. Then car driver exited his vehicle as he started yelling and repeatedly using obscene language and was trying to detain him and by grabbing onto his shoulder. The aggressive behavior of the car driver terrified him moreover it became apparent to him that this wasnt the safest place to be at that moment. He decided to leave the scene of the accident for my own safety.

It is obvious that the car driver did not behave in a civil manner by yelling and trying to detain my son and the Toronto Police officer explained that this was perfectly reasonable, and it is known as Civil Arrest...

Can we consider it to be a Civil Arrest?

The private citizen right to arrest without a warrant under s. 494 of the Criminal Code only applies to criminal offences, or an indictable offence.

Indictable offences do not apply to the HTA and offences under the HTA are not criminal.

The right for a cop to arrest without a warrant under the HTA is limited to subsection 9 (1), subsection 12 (1), subsection 13 (1), subsection 33 (3), subsection 47 (5), (6), (7) or (8), section 51, 53, 130, 172 or 184, subsection 185 (3), clause 200 (1) (a) or subsection 216 (1).

Section 200(1)(a) expressly states;

Duty of person in charge of vehicle in case of accident

200. (1) Where an accident occurs on a highway, every person in charge of a vehicle or street car that is directly or indirectly involved in the accident shall,

(a) remain at or immediately return to the scene of the accident;

...

Every private person may also arrest without warrant any person whom he or she finds committing any such contravention mentioned above.

The police, but not a private person, can also arrest without warrant a person breaching s. 177(2).

From what I gather, your son was not leaving the scene before the guy grabbed him, therefore, in my view, he had no right to touch your son at all. In fact, you can argue he assaulted your son.

From what youve told us, the guy also never informed your son that he was under arrest, if he is now claiming he was arresting your son.

Once he arrested your son, he was also required to inform your son of his rights under s. 10 of the Charter. He didnt do so.

The guy had no legal right to arrest your son for the accident itself. If hes claiming he arrested your son for the accident, then it was an unlawful arrest and your son can sue him.

The HTA provides no immunity for te illegal action of false arrest when he acted on his own and not at the request of a police officer. The HTA only provides immunity from false arrest if an officer requests your help in arresting someone.

Thus, a distinction is made proving he is provided no immunity.