And second, the point of my rhetorical question is that it's completely sexist to assume that Sherlock was the only person in the room whose decisions mattered. Mary chose to go. We saw her and her husband discuss, together, which of them should go to the Aquarium to meet Sherlock, and she and John mutually agreed that it should be her. She was an adult human being who made her own choices that led her to that situation, and focusing exclusively on Sherlock's choices is dismissive of Mary's personhood, her agency as a responsible adult. The whole idea of the "vow" is condescending in the first place -- the notion that an ex-CIA agent and highly trained mercenary/assassin was so helpless that she depended on the protection of some drawing-room detective is just stupid. She was the most qualified protector in that room, and she made a choice to protect Sherlock. He was the victim in that situation, the vulnerable one who needed rescue, and she was the hero who chose to give her life to save him. That's the fair, non-sexist interpretation, the one that honors her as a person.