I would NOT list tuition paid by anyone else, be it from a scholarship or a grandparent or even your parents.
If you are claiming financial independence in college, they are looking for any evidence to the contrary. However, for graduate and med school purposes, FAFSA automatically assumes you are financially independent - it is not an issue (but individual med schools can and do assume that you will receive family support). Therefore, I would not include any information on FAFSA that might change that assumption.
The fact that two different FAFSA reps gave you 2 different answers is pretty indicative of how ****ed up this system is. Take the advice of the rep who said don't list it...but be sure that whatever income you list on FAFSA matches precisely to your tax returns, and also any investment income you may have is reflected in your "assets" on FAFSA.