Jmo, except for the shoes and the cell, all of those items could be easily kept inside a wristlet or wallet, at least at first. (Actually even the cell phone could fit, maybe.) Then as she took them out to use for just a second, IMO, they could be easily misplaced. ...eg say you don't immediately secure the IDs back inside the wallet after showing/using them, then as you're leaving someone from the table shoves them toward you and you just grab them up on your way out, not bothering to secure them. Then if you do drop stuff later on, just my experience, it is easy enough to just pick up the big item (the wallet), forgetting that there are loose items too. I am actually quite paranoid about this when I am out and get teased for my incessant checking in my wallet. In fact I dunno if Lauren had pockets that night but many of my outfits don't and that's part of the problem. I had assumed that her pants at least wouldn't have pockets as they were, iirc, described as leggings.
ETA...Everything ^ is 100% just hypothetical, Jmo and keep in mind, I am someone who is constantly "losing" things right in front of my nose.