Originally Posted by
WineCountryUA
It's your choice to check another travelers bag as your own and not a rule violation -- but at some non-US locations, you may be asked if you packed the bag.
If you were not traveling and someone used your card, that's a different issue and could become a problem if discovered.
Right. The original question sounded a lot like that was the scenario -- OP not traveling and trying to figure out a way to get a free bag.
In this case -- UA isn't going to know, or care, that the *A agent gave you a break. The only thing I'd be worried about is how much you trust the friend, because if something illicit were discovered, you're going to be the first person they find.