I think Mr. Casey in the second reading speech gave quite a long list of offences that could apply to this type of conduct. The one most applicable would be aggravated assault, which is assault causing maiming, wounding, etc.
In terms of legally, there is no gap. The conduct can be prosecuted. From what I understand from the sponsor of the bill, those who support the bill wish to actually denounce a specific type of aggravated assault, and that is the kind where there is actually an intentional commission of causing serious pain or suffering, and not just simply the intentional causation of assault which causes maiming or suffering, but actually that the injury be intentional, that there be an intentional assault, plus an intentional causing of pain or suffering.
Of course, the current law doesn't require intent on both sides. One simply needs to intend the assault. If the assault is to such an extent that it causes maiming or wounding because the person is reckless as to the consequences, that is sufficient under the law.
It's more of a denunciatory purpose, I understand, in this bill, as opposed to actually plugging a real legal gap.