Welding slag under window tint

[James88215]

So had my windows tinted yesterday, I have an older car, been in the family since 1992 and it's a 1990. So as the guy was professionally installing the tint, he asked my if the car had ever been in a wreck. Since it's been in our family, no, but the 2 years before it was possible. Anyway, he said there was what they call welding slag all over the back window, which is usually from a car getting into a wreck and being worked on. He said there isn't anything he can do about it, and that if he tried to chip them out, it's embedded into the glass, so it would make it look even worse. So he just tinted over the so called welding slag. My question is, has this happened to anyone else, or is this very common? Because I didn't notice it too much at first, but there are lots of little spots that look like air bubbles, and when I took it back, he said that'a from the welding slag, and there is nothing he can do about it, unless I want to get a new back window. Is this correct, does this happen very often and is there really nothing that can be done about it? Thanks.

[thecityxignites]

It happened on my cavalier, but it was from when I was cutting the rear deck with a grinder. What happens is it melts into the glass, and causes little divots. I had my tinter tint over them anyway.

[DubNDodge]

Hate to bump this, but I also have some random black (small specks) stuff all over my passenger rear window. Noticed it when I was washing it the other day. Not sure what it is, but it wouldn't come off.