My guess is that if you did poorly on the exam, so will other students. As a former teacher at the college level, trust me, this will cause the professor to look at the test.

Sometimes professors just get overwhelmed (like students) at the end of the semester and will just put a test in front of you, or use one from a previous semester, or whatever.

Is it fair? good lord no, but professors are human too. I suspect your professor will not grade this exam too harshly and you will still get your A.

I know that's what I would have done if everyone bombed a final I administered.