In this case, Florencia's. The medals collecting was her thing, and is what opens that path.
I guess what bothers me most is if just not going to the mansion at all solves everything, why Roswell didn't call it off before? Besides that, I'd like a explicit explanation how this version of the events, makes using the medicine a viable option. Berek07's conjecture is good, but I was hoping that the story would have told me that.