It's somewhat surprising, but then, men can still be significantly more prone than women to consider themselves expendable, and still outsurvive women in shipwrecks if both genders tend to be non-self-sacrificing enough for the situations to devolve to "every man for himself." For purely physical reasons, men are more likely to make it out of a panicked crowd alive. I'm a bit surprised that the Titanic scenario was as exceptional as it was, but I would not necessarily have predicted that relative rates of self sacrifice would dominate survival rates.

If a reliable study were to find that women are as or more likely to risk or sacrifice their lives to save non-progeny compared to men, it would certainly be sufficient to change my mind.