I guess it may have been burning it, I don't check often enough to know. I also find it weird that there was no low oil light, the temp gauge stayed normal, and everything everything seemed fine until it's last 5-10 minutes. If it were burning oil it's weird that they didn't notice that before. Usually when I take it for a change they tell me everything about it. What fluids they topped up, any alignment issues, how much brake pads have worn, etc. The last oil change I remember they took it out for a drive as well. They are usually really informative. This time, not so much.
It made my day about 100x better when they said everything would be covered! Now I just have to tolerate this dam Kia rental for a few more weeks!