Which is more important for a class in your opinion attendance or test grades?

Some of my classmates were complaining that a kid who has missed like 10 days of class received a higher grade than they did overall for the course. He got great grades on all his tests even higher than the students who have never missed any class and now the teacher is contemplating changing his grade because of all the complaining which I think is bull. He studied hard just like everyone else. Just because he missed a few classes doesn't mean he should get less of a grade. By less of a grade I mean she was talking about taking it down about one or two. Meaning if he would get a high B it would go down to like a C or high D. How unfair!!! Or at least to me it is.Which is more important for a class in your opinion attendance or test grades?
This depends on the nature of the class. If it was strictly lecture then I think the grade should stand. But if the class involves participation such as a lab, then attendance is important.