I agree with your assessment, baker. No one knows what it was, so candy, thumb drive, Ovaltine decoder ring… it could have been anything small.
https://www.yahoo.com/news/u2-cancels-berlin-show-bono-loses-voice-072149826.html
From the article: Cabal member can't get his medications anymore. Goes to take a nap. (Ok, not really from the article, but should be.)