I have just read the story of the rescue of Matt Winter and recall several occasions in the past when my split paddle twisted and know how difficult is to get it reset in rough water. In my case the problem is compounded by the fact that I am far sighted and find it very hard to see the setting without my glasses. I solved the problem by drilling 2 depressions in the shaft and lengthlock so that they are perfectly aligned when the paddle is set correctly. I then filled the holes with a dab of day-glow orange paint and my problem was completely solved. I have since reset my paddle length and angle in rough water without a problem whatsoever.
PS be sure to use a drill press so that you drill a depression and not a hole in your paddle shaft!