I'm gonna guess that her Sympathy for you is really low because her Temporary AI just kicks in. If her Sympathy is high enough, the game should give you those 2 choices. And Jun might need to have Both Arms and Legs. Well, at least, of course, she needs both Arms. Other wise how will she gonna do a karate-chop?
I didn't even know about this, and I just realized that Jun might need to have both Arms and Legs. I thought the game will give you 2 choices for you to choose anyway. I never encounter this myself because I've been playing this game for so long now. On every playthrough, I always manage to get both Arms and Legs before that Woman finally comes to attack. I also can't be able to make Jun hate me too. I still haven't figured out how.