I could just be having a paranoid moment right now

My thoughts seem to be all over the place today. But something a little strange has happened.
As I mentioned on my post 'More than just friends', I deleted my friend from Facebook last week. About an hour or so before I deleted her I had received a friend request from some random girl, which I ignored. This request also came not long after my friend finished work for the day to go on leave for a couple of weeks. Unbeknown to me, this random girl also sent me a PM. I didn't see the message until later that evening as it went to the 'other' folder.
What I found was rather shocking , to say the least. It was photos of conversations between the random girl and a guy plus naked (close up) selfies of him. The girl said his girlfriend needs to know what a scum and cheat he is. The twist of all this is... .the couple both work at my workplace. Not only that, but the girlfriend is actually the sister of my friends new (I suspect) shiny toy 'crush' who also works at work. The boyfriend also works in the same team as the 'crush'. Twisted, I know!
It makes no sense to me why I would be randomly targeted with this information when I am not overly close to the couple.
Co-incidentaly, I had only recently become friends with the sister on Facebook. Obviously, my friend whould have seen that as they had become friends earlier this year, and perhaps not have been too happy (I am guessing) about it. Funnily enough, I also gave the girlfriend a souviner a couple of weeks ago from my recent holiday. I didn't give my friend anything, which I normally do. This could be irrelevant though.
Whilst the thought crossed my mind at the time that my friend may have somehow been involved, I ended up thinking I was jumping to conclusions and put it down to mistaken identity.
I couldn't view the random's profile as she deactivated by the time I saw the message. Fast forward to today and I see that the girl has activated her profile again, so I had a look at it. It clearly is a bogus one. She only has 2 friends, which were added a few days ago. Neither of those people have any connection to me or the couple involved.
Now for the final twist... .the random girl is actually following my friend on Facebook! So, out of all the people associated to the couple, this random girl has connected with only my friend and I
I could very well be trying to put two and two together in my paranoid mind, and coming up with 100, but I find the timing and people involved very suspicious. Obviously, I won't be acting on this information. This could very well jeopardize my job if I was to show people or get involved.
Is this something a BPD could be capable of? I still find it very odd that my friend seems to have gone to ground and has not queried me about being deleted from Facebook. That is out of character for her given past experience. I do smell a rat - just don't know which rat it is
