There is no correlation between exercise intensity and likelihood of injury, this is nonsense. You could e.g. just as well make one wrong move when going for a one rep max.
Going for one rep max is intense. If it weren't, you could get a better max.
That's not what exercise intensity means, clearly you're not even remotely familiar with the domain.
In the context of weight lifting, or neuromuscular demand, a one rep max is very high intensity exercise. In the context of metabolic demand, it is not.