Let’s take into consideration the three elements of self-defence.
The first element requires the person to believe, on reasonable grounds, that they are under threat and that force must be used. That is both an objective and a subjective element. The subjective aspect—what the person thinks—is considered first. Then, the objective analysis is done, whereby it is determined if the act was reasonable.
The second element is exclusively subjective. The only thing considered is the person’s intention. It must be established that the person intended to defend themselves, rather than continue to commit the crime in progress.
The third element is purely objective, as the two other elements are used to determine the third. It must be decided what kind of reasonable grounds the person had regarding the threat and what that person’s subjective intention was. All that is taken into account when deciding whether the person acted reasonably.