Time After Time Mystery

Ok, so I have been rewatching all my DVDs and introducing my fiance to this lovely little guilty pleasure and we noticed something. They always play it out that Roxtona nd Marguerite have a thing for each other, but then we caught something interesting in the "Time After Time" episode. In it Roxton finds out from Catherine that he dies in June 1920 from reading Marguerite's diary. Then at the end when Marguerite is reading her diary and reads an entry from a few years later (I believe 1923), a month after Catherine's grandmother is born, she talks about "one death more" and "the man she loved" and how she thought she was a hero for bringing him home and instead she brought him home to die. At that point Roxton was already dead so who is it? If she was a hero for bringing him home obviously it was someone on the expedition with her but it's not Roxton. Malone? Challenger? Summerlee (ick!)? Anyone have any thoughts on this. We know that Malone died in London before going back to the plateau, according to Catherine. So anyone else think he's the one she hooked up with? She did spend a lot of time teasing him and you always tease the one you love. It seems to be more than just a continuity mistake.