I reckon she text Bethany saying she was freaking out and had seen someone. Bethany was the floor below and probs said something like ‘I haven’t heard anything, don’t worry I’m sure they’re all fine’ and that was probs enough to reassure her. She had no idea how severe the crime was - probs thought it was an intruder looking to commit a burglary. I really do feel particularly for e and x who I just think were so unlucky and probably went through absolute hell in the moments before they died
I was thinking this about Dylan and Bethany. Maybe Dylan thought the person she saw was someone that came back with X&E, or a friend of E's and they had had an argument, hence Xana crying and this person was making a swift exit because he had upset his friend's girlfriend or just because Xana was upset about something else? Yes, the mask looks and sounds suspicious in hindsight but we've just had covid - people do still wear masks. She could have said to Bethany "A random guy just walked past and left and I can hear Xana crying - Shall I go check on her?" And maybe Bethany said, "It's ok, Ethan's with her, sure she's fine". Just theorising. There's nothing stated in the PCA that he was covered in blood, although it's hard to believe he wasn't.
I personally don't think he saw Dylan. I think the angles of the corridors/rooms, the fact that the adrenaline must have been absolutely rushing through, the fact that he had probably already murdered more people than he initially set out to meant he was just wanting to get out of there and he may have even had a hood up that obstructed his sight. When you have a hood up, you can't always see to the side of you very well, can you?
Again, purely thinking out loud as I have no idea about what they were all like personally but I also feel like obviously, M&K were best best friends, and I feel like X hung around with them a bit as well as living together, and I think Bethany was quite close with Maddie as they were in the same sorority, wasn't she, but I don't think it looks like Dylan was "besties" or really close with any of them besides being roommates, which is totally fine, not suspicious or anything but maybe it wasn't obvious to her that anything was wrong if she wasn't that close with them? She may have been closer with Bethany as they were both on the bottom floor, prior to her move to the middle floor? I really feel sorry for Dylan, the amount of guilt she must feel is immense.
Also the posts about Xana's mum. I don't know if it's been mentioned but early on in this case, one of her friends stated that Xana got on with everyone, especially her friend's mums because she wasn't close to her own mum and her friends' mums all took her under their wing? I'm sure I remember that being said but can't remember the source. Estranged, or not, if my daughter had just been brutally murdered, I think I'd be considering drugs as well.