China - by law - requires animal testing. Products sold in China are tested on animals. So Mac (or Estee Lauder) uses animals to test those products which they sell in China
I think you are confused. Many companies use products that were once tested on animals, a very long time ago and not by them.
If you're trying to say never buy a product that contains something that was ever tested on animals, then there would be very little to buy. If you're saying they use new ingredients they test on animals, then you're wrong,
The discrepancy, and your confusion, is who tested the ingredients they use and when. If they didn't do it, but it was once done a number of years ago by another company, possibly even for medical reasons, then they can sell in both continents.
As for the op, I think it's fairly petty, if you want your lipstick back, get it next time you see her.