I was baffled today that an onCellEdited event seemed to be firing twice for every edit. I could not figure out why (no loops or anything). When I finally decided to RTFM the answer was just sitting there waiting for me.
This seems like the kind of thing it would be easy to omit from the docs, but it was right there with a colorful background in the first place I looked. Thank you IA Documentation team for putting together a thoroughly useful and impressively comprehensive resource.