Actually, a quick web search will reveal a huge body of research and statistical analysis regarding fighting back, at least in regard to rape, and whether it's helpful or worse. It's one of those things that a self-defense instructor needs to be read up on before he teaches self-defense. Rape prevention is one of the reasons a woman shows up for such classes and it needs to be addressed.
It makes me wonder if anyone has put as much effort into more general assault; what the breakdown is for fighting back vs. taking a more passive role. Maybe assault is too general to study ... too many varied circumstances, from the bar fight to muggings to robbery to attempted murder, etc. Even within rape there are many different types of rape and rapists, though they have been broken down in a fashion useful for self defense. If you have your wits about you, and time, you can analyse your attacker's type and use the info to your benefit.
You can pressure a student so that they respond as if the situation is real, or at least real enough for them for training purposes. This is not something an instructor should do unless A) their uke is armored or very tough and experienced and B) They know how to deal with the aftermath. Heap enough pain or trap someone, even in a friendly and familiar environment, and they will slip into fight/flight response. Sometimes even a verbal provocation or hypothetical situation will do it. For example, I got trigged by a sentence during a sparring session. "Kami, when he's through with you, he's going for Andrea." Andrea being my daughter. My sparring partner, a very experienced and excellent martial artist as well as an LEO, saw my look change and covered up, going into full defense. In the back of my mind a very small part of me was aware enough that this wasn't real so I did pull my strikes ... barely. I certainly hit much harder than I would have just playing around, harder than I consider advisable, much less polite. If Mac had kept pressing me instead of covering up I think it would have obliterated even that small bit of control. I'm glad I didn't hurt him. Suffice it to say that it is possible, sometimes shockingly easy, to sink a person's awareness of their 'safe' environment and have them training under pressure. Techniques vary. I hear some instructors will suddenly engage a student in the dressing room after class, or grab them from behind when they're not paying attention during down time in class. Gets the adrenaline pumping.
With a normal, healthy person who hasn't had trauma in their lives or has dealt with it adequately, this is a great tool. However, the B caveat is there for a reason. Trigger a rape victim, and when she comes out of her attack (or panic) she will fall apart emotionally and you better darned well be prepared to help. You can't just leave someone broken down and figure it was a great, intense session and they learned something. If you don't know your psychology you can get into trouble and leave an emotional mess that will do that person more harm than good.
-- Kami, who wishes she didn't have so many friends who've been raped.