Why does a coincidence measurement in, for example, a scintillator paddle detector identify a particle as a muon? Couldn't it be some other particle that happens to travel through both detectors? Or say you have two Cherenkov detectors with one about a metre above the other. Then if they both detect a signal close together would you be able to say yep, that's a muon, and if so why?
Here's the link that seems to me to suggest that the coincidence measurement is what allowed them to say they've detected muons. They don't give details of any other identification method unless I've completely missed it.
Statistically I think most detections would be muons because of their sheer number, so is that what they're basing their statement on?