A dent puller can't put a crease in metal unless the panel was already stretched or the glue let go at an angle. The puller itself doesn't crease anything, it just grabs a stud or a tab and pulls. If it slipped, that usually means too much force or the tip wasn't seated flat, which can lift the metal instead of pulling it out smooth. A real crease means the steel bent past its yield point, so now you're looking at hammer and dolly work or a stud welder and shrinking, not just another pull.