I just read this thread for the first time and this woman's accusations against the priest are simply not believable to me. I'm with Ladislaus on this one. Regardless of what else is going on in the SSPX regarding abuse by priests, this case stretches credulity on so many levels. 
You can buy a door handle/lock at ANY hardware store for pretty cheap and there's this invention called a telephone that you can use to call this organization called the police if you are in danger. I've called the police on my neighbors several times just for loud music and barking dogs. I think the threat of being routinely raped would be a bit more of an incentive. 
Funny how someone who can't manage to use either resource sure found a way to reach out to CM, The Remnant and elsewhere to broadcast her tale.

  

This assertion that anyone who doesn't instantly believe every word of any accusation somehow condones rape or pederasty or whatever the case may be is akin to the Jєωιѕн ploy that anyone who doesn't believe that 6 million Jєωs were intentionally exterminated by the nαzιs must be sympathetic to the h0Ɩ0cαųst and would have done it themselves if they could have

Yes, we're "accomplices after the fact," and just plain evil if we don't get behind this story and believe it, and do everything in our power to right the supposed wrong as good little Social Justice Warriors should do. Seems very cryptojew to me. 

Do you believe there are men and women who don't know how to check their tire pressure? …that there are men who are forcibly sodomized but do not call the police? … women who are raped but do not call the police? …parents whose children are raped but do not call the police?

Yes, I also know there are people who think they were raped by aliens, have hybrid offspring with aliens, and communicate with aliens on a regular basis. Likewise there are people who firmly believe they interact with jesters from another dimension when they smoke DMT. 
Similarly there have been lots of false prophets like Joseph Smith made claims to have been visited by angels and received supernatural revelations. In so far as this woman's particular testimony I find that any competent defense attorney could shoot huge holes in it. 

After reading your explanation you obviously considered changing the locks at the time of your troubles, fair enough. So now I ask: why didn’t you use the back of a chair, a wedge, a bar, a 2x4, or something improvised to jam the door? There are easy and inexpensive ways to stop an intruder.

And so when I leave my apartment for work or any reason, Arzuaga can enter the apartment with the stolen key and be waiting when I get home. What is the purpose of the chair, wedge, etc.?

And so when I leave my apartment for work or any reason, Arzuaga can enter the apartment with the stolen key and be waiting when I get home. What is the purpose of the chair, wedge, etc.?

For future help, take a piece of tape or a piece of paper and put it at the bottom of the door when you leave. When you get home check to see if the “seal” is broken. If it’s broken, immediately call the police and your problem is solved.

Also, did it ever occur to you, at the time, to go to a halfway house or to the police when you thought he was entering illegally? 

Wheter Miss Kauffman is lying or not, I think that it is disgraceful that she has been so mistreated by fellow Catholics.

We don't all have to believe her, or agree with her, but I think that she should be treated with more respect.

About the case, I believe that it is possible that she had a colorful relationship with the priest, but she had no intention to take things so far. We all know how people in general like the attention of the opposite sex. Maybe she was young and inexperienced, and liked the attention that the priest gave her. She might have even trusted him to go to her place just to talk, not imagining that he would take things so far. Once he had her trust, he could manipulate her and take advantage of her. Possibly, as time went on, she realized that he manipulated her and took advantage of her. It is possible that there was physical violence, which most people would qualify as rape. As she trusted the SSPX leadership, she waited on them to take action. It was the 1990s. Things were different. We had no internet and information as we do today.

I am just imagining a scenario on which we could justify and accomodate some of the different versions of the story.

Also, why would Miss Kauffman still be discussing and answering questions about this after so many years? What is in it for her? If she is lying, it doesn't add up either. She has nothing to gain here.

As a conclusion, we have the facts:

The SSPX acknowledges that this priest had an extremely improper relationship with a parishioner and SSPX school teacher, and yet, the leadership allows him to function as a regular priest. That is puzzling enough. Rape or not.

It makes you wonder what a priest has to do to be expelled from the SSPX. Apparently, the any crimes that are unforgivable are Sedevacantism and "disobedience" to your superiors. Once made a priest, you can getaway with anything else. Even with fathering children and raping youngsters. We are yet to hear about murder.

About the case, I believe that it is possible that she had a colorful relationship with the priest, but she had no intention to take things so far. We all know how people in general like the attention of the opposite sex. Maybe she was young and inexperienced, and liked the attention that the priest gave her. She might have even trusted him to go to her place just to talk, not imagining that he would take things so far. Once he had her trust, he could manipulate her and take advantage of her.
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The SSPX acknowledges that this priest had an extremely improper relationship with a parishioner and SSPX school teacher, and yet, the leadership allows him to function as a regular priest. That is puzzling enough. Rape or not.

That's a nice fanciful narrative, for which you have no more evidence than anyone else's version of the story.  And that's precisely the problem here.  It's he said vs. she said ... with nothing else to go on.

And, yes, it absolutely matters whether or not this was rape.

And your characterization of Kauffman as this naive young girl who had no idea what she was doing but was manipulated is also not based in any fact and also would defame Fr. Arzuaga more than would be just.  It is not permitted or correct to say, "Well, it was bad enough that he violated priestly celibacy, so there's no harm in piling on the additional allegations."

Evidently the SSPX have witnesses who testified to the nature of their relationship outside of these sinful encounters in such a way as to make their observations inconsistent with rape, and the key thing makes absolutely no sense whatsoever.

In one sense, though, part of your narrative is not implausible, where Erica had misgivings the entire time, being conflicted in conscience because she knew what she was engaged in was sinful, but not saying anything, and then as the years pass, these regrets get amplified into "I was unwilling" and then get translated into "rape".  It doesn't have to be a matter of conscious lying.  This kind of thing happens all the time, where a young lady or woman somewhat reluctantly (in her own mind but not expressed outwardly) engages in such activity, and then after regretting it later, in retrospect, this initial unwillingness gets amplified into a resolute "no" on her part ... and thus the original incidents get transformed into "rape".

Just can't get past the key thing.  CHANGE THE LOCKS or ask your landlord to.  Would have taken a 30-second phone call to the landlord.  "Someone obtained an unauthorized copy of my key and I need the locks changed because I'm concerned for my safety." ... even if she's afraid to report rape per se.