Ralph's inability to shut up is always what does him in.

So here's the real timeline: they got separated while he was arguing with the cops. He starts tweeting about her, goes to Irish pub, tweets more, phone call with Amanda's mom, finds out where Amanda is, deletes his tweets, goes to the hotel and leaves his luggage behind at the bar.

The "it was a work" was just a bullshit cover story for him flipping his shit after she went missing. As we knew all along.