However, it does seem logical that if some commotion was going on inside the house and Stacy heard this she might feel compelled to flee the house clad only in her panties.
The matter of the absence of the door to Suzie's room is interesting and I was unaware of this. But if the door that was previously to the converted garage was removed there would have been no privacy.
This is actually the scenario that makes the most sense to me. If you can put yourself back in a teenage mindset, how many of us had parents that wanted us to let them know we had gotten home safely, even if they were already in bed? That was always the policy in my house- even if it was late and they were sleeping, I should poke my head into their bedroom to let them know I was home. We don't know for sure if Suzie had planned on spending the night with Janelle, but either way I can see it being reasonable that after they got ready for bed she thought that she should go let her mom know she was home. If Sherrill knew that her daughter was planning on getting home in the wee hours of the morning after a night of graduation parties (which she would have surely known would have included alcohol), she would have surely asked Suzie to let her know she was home safely. On the other hand, if Suzie knew her mom was planning on her being at a friend's all night and had not only come home but had also brought an unexpected guest with her, it would be logical for her to think the right thing to do was to go give her mom a head's up.
If Sherrill was being subdued in that room, obviously Suzie going in there would have been a problem. If that started a struggle and there was screaming, it could have scared Stacy enough that she felt the need to flee. Without the door, it is understandable that she didn't take the few seconds necessary to grab her shorts, because she knew she could have been seen literally any second without warning. I remember seeing a picture of the bedroom one time but haven't been able to find it again since then (if someone has it, can it please be posted in the links section?), but would it have made sense that Stacy got to the door by sliding across the bed rather than walking around it? I'm just trying to think of ways that I might move around in a dark room that didn't have a door if I was trying to be as inconspicuous as possible.
There is one issue with this, though. The only reason I see it making sense for the perp(s) to wait that long without trying to get to the girls is if Sherrill was the target. Assuming that they could keep Sherrill subdued and quiet for 30 minutes+ while waiting for the girls to get into bed makes the most sense if they were thinking they would be able to get out of the house without drawing any more attention. This only leaves us with 2 options: there is something we don't know about Sherrill that was the motivation for her being attacked, or, it was a crime of convenience based on someone realizing she was a woman home alone and there were open windows (I'm not sure if this has ever been confirmed, but would be likely given the smell of varnish).
Having acknowledged the possibility, I've always had a hard time accepting that it was a crime of convenience. I think the fact that this happened on graduation night is significant. It is a time of emotion, a time of pride, and a sentimental day. Even if they weren't going for the emotional element of it, and assuming Sherrill was the target, it was at the very least a night that had long in advanced been planned for her to be home alone. I also think Suzie being set to testify soon is likely significant. Would it be possible that someone thought they would go mess with Sherrill as a way to scare Suzie and things got out of hand? I know these are things that have all been argued back and forth for a long time, but when you have a triple disappearance that goes unsolved for going on 20 years, I have a hard time accepting that anything is simply a coincidence.
Ramble over.