That is what you get if you use a squeegee and there is a piece of grit embedded in it.
I avoid squeegees. But if I were to get someone to squeegee a wet film for me, I'd get someone like df Cardwell or Charles Webb to do it for me, but only if they used their really old and tried and true and scrupulously cleaned squeegees, and only then with Photo flo first.
Why would you need to use a squeegee anyways - Photo flo and air drying works great (in normal humidity).