Can you elaborate on this process? I am also in a similar situation as @rootatroot and emailed GEM about it as well. The conversation was as follows:
""" Me: I was curious about GEM Associate/University Fellow. Is it possible to be only considered for these two forms of the Fellowship? Additionally, if I accept a non-GEM internship for the summer, would I be required to renege that position in order to pursue the GEM Fellowship?
GEM: No, all applicants must be available for employer selection.
"""
So I am a little confused, but it seems you must accept the offer if a GEM Employer gives you an offer.