Why does the Torah insert the (otherwise superfluos) phrase "Ein la'Na'arah Chet Maves"?
Sanhedrin, 73a: To teach us that one is permitted to kill the one who is chasing a fellow Jew to kill him 1 or to rape him, or after a Na'arah Me'urasah to rape her to save the victim - whether it is a case of a. Chayvei Misos Beis-Din - "Na'ar" ("Na'arah" is spelt without a 'Hey, to read 'Na'ar) = 'Zeh Zachar' and "Na'arah" - 'Zu Na'arh ha'Me'urasah'; b. "Chet" - 'Eilu Chayvei Kerisos'. c. "Maves" - 'Eilu Chayvei Misos Beis-Din'. 2
What is the significance of the comparison of the Anusah (the girl who has been raped) to the victim of a murder?
Rashi #1: To point out that a girl who is raped in a location where there are no witnesses is no less an Oneis than the victim of a murder and is therefore Patur.
Rashi #2 (citing Sanhedrin 73a): The Torah is coming (not to compare the Anusah to the victim of a murder, 1 but) the latter to the former - inasmuch as, just as one is obligated to save the Anusah even by killing the rapist 2 if necessary, so too, is one obligated to save the victim, even by killing the pursuer, if need be.
Seforno: With reference to a girl who was initially raped but now wants the rapist to continue 3 and the Torah refers to her as an Anusah - just like the victim of a murder.
The Gemara does in fact, go on to learn Anusah from from a man who is being murdered inasmuch as, just as regarding murder, one is obligated to give up one's life rather that transgress, so too, must one give up one's life rather than commit adultery or incest. See Torah Temimah, note 189.
Seforno (citing Kesuvos, 51b): Even if she asks her rescuer to allow him to finish the act, she is considered Anusah, since the Yeitzer ha'Ra to continue was forced on her.
