IF it happened it could be any number of things that would seem innocuous to anyone around him. He could've been (For lack of a better word I can think of) hypnotized to write down when and where leaders of the forces against Odium will be, and leave it on a windowsill with a particular glyph written on it. If I recall correctly(It's been awhile since my last read; Oathbringer's release) Odium can view Roshar much as the Stormfather can? In the Everstorm, I mean? He'd just see it and send an Agent to pick it up. Much easier for Odium to win if he knows in advance for example, Jasnah, Shallan, and Dalinar are going to be at somewhere a few days in advance and can set up a nice big ambush.
Or end up stabbing Dalinar in the back at some point, literally. I could see something like he walked up, struck, then snapped out of it with an 'Oh, snap. Whaaa?'
I know that I'm probably wrong. But I reaaally like the Theory, and it would spin, I think, into his whole "mentally broken" thing he's working through right now. No matter what Brandon chooses, I'm sure it'll be a nice trip through mayhem and storms.