What if that person was on her way to her next work assignment? Would that change your mind?
Keep in mind that unless you purchase and confirm, with either money or miles, a first class seat, you are not entitled to it. Sure, they probably should give it to you over a non-rev. But it's not guaranteed.
If first class is important for you, pay for it and confirm it beforehand. Then you won't have to worry about these things and you'll have much more peace of mind when you don't have to stand around at the gate waiting to see if you get it.
Otherwise, you take your chances.
[This message has been edited by mdtony (edited 04-26-2002).]