Hahaha, that is a fantastic story! I would have been panicking about keeping the camera above water too, that hand-off must have been something special to witness. Fortunately, inflatable kayaks are pretty stable (albeit slow). The only time I've rolled was on a whitewater stretch of river and it was my own fault.
I'm happy to be able to share memories of the San Juans with you. They are just a straight-up special place.