Harmful and half-harmful

In tooth damage, there is a liability on the part of the tortfeasor and there is a liability on the part of the beneficiary. When the animal entered the property of the tortfeasor intentionally, the owner is obligated to pay for what the animal caused and, in mutual damages, for what it benefited, except that the tortfeasor collects whichever one he wishes (usually the tortfeasor's fees are higher).
 
What is the ruling in the case where an animal causes damage for which half of the damage is paid, and at the same time there is also a beneficiary? Is the harmer obliged to pay a fine and that's it, or is he obliged to add another half of the beneficiary's fine?