On Ellie's laptop? I didn't realize that if you snooped on it you had to do something. I can only tell you what I personally have done, and I had no problems leaving the laptop after I finished.
I opened her Whistle app (I think it's second down on the desktop screen) and clicked on one of the girls: Samantha, Chloe, whomever. I read through each entire conversation, but since the game can't really tell if you're actually reading, just moving the scrollbar all the way to the top of the conversation (it begins on the bottom, on the right of the screen). I then moved on to the next girl and went through that conversation. After finishing all of the conversations, I was able to exit with no problem.
If you do the above and still have issues, you may want to ask someone else (possibly WhitePhantom) for help, because it sounds like a bug. Note, however, that if you're using a compressed or Android version of the game, you'll want to search this thread for the person providing that (they aren't official or made by WhitePhantom) and reach out to them to see if they might be able to help you.