Could be but this kind of stuff happens at all water levels. I always plan my camp sites away from flaky walls and also aware of possible water falls / flash floods. I saw a waterfall develop on night coming off a wall across from our site that was dumping boulders and trees into the lake. Not a cloud in the sky where we were camped but a micro burst about 12 miles away produced a flash flood that flowed off the wall into the lake. .....
For Tyler Knudsen with the Utah Geological Survey, watching a video of a cliff wall collapsing into Lake Powell is a fantastic example of a normal event.