Tom, I would say you absolutely did the right thing here. I know that statistically speaking 98% of the time if someone says they were raped that means they REALLY WERE. It is very important to listen to this and to get these people help.
Someone mentioned being the person that can listen to the people that come to your parties. I would say That is a great idea. An even better one is to look at abuse outside of BDSM. You will find that BDSM and abuse are quite different. Abuse can take many different forms and at times is very subtle. I know that in another thread someone mentioned ignoring the sub as punishment and generally that was considered too cruel. Some would consider that as abuse by neglect outside of BDSM.
But then again, it is very hard to take care of everything. You can't screen everyone that comes to your events. What you can do though is be a resource to those that are there. Provide people with information on safe and healthy relationships, etc. This is a small thing but it's sometimes a first step to getting someone out of a place where they shouldn't be.
Lastly, the question of abuse resulting in pervyness. I don't buy that. I mean I can see how it could, but if you are liking being punished because you feel badly about yourself, maybe you should re-evaluate what you are doing first and sort things out. There's nothing wrong with being a survivor of abuse, but playing while feeling badly about oneself at least to me seems REALLY unsafe.