The shape of that would suggest that it couldn’t have been caused by an airborne pinball. And the fact that it has a discolored “dirty” border around the divot would also suggest that it’s been there for a while (even if you just noticed it).

As for fixing... not sure, but you can put a small piece of Mylar over it to reduce its affect of the ball movement and keep it from getting worse.

I would send Chris (HEP) a picture of that and ask him what to do. He might be able to point you in the right direction. Man, sorry that happened to you.

It looks possibly caused by a screw coming through from under the playfield. Can happen if too long a screw is used. That could have started it then the ball did the final damage that made it noticeable. I would check under playfield in that spot. It may be possible to press the blemish down so its relatively flattened then cover with small Mylar patch.

It can be filled and touched up, but it is time consuming to get the color match right. It probably won't get any worse with home play. And that looks like someone dropped a screwdriver on it a long time ago. I think the airball just drew your eye to it.