This hypothesis would make sense. That's why coffee is such a no-no with AF. I've had a few venti Starbucks in a day with AF and I would classify myself as a danger to society -- seriously. I used to not wear my seatbelt in case I had to jump out and kick someone's ass. I was a raving lunatic.
Caffeine does nothing but make your stress hormones stay in your body longer, i.e. keep that amygdala on high alert.