I have encountered. and made it repeatable. I jump down from a cliff into shallows, i click to walk across the cliff-face, causing him to sidestep. After sidestepping from the bordering grass into the actual shallows i can run at the speed set at the top of the cliff. also with no stamina cost. i have screenshots if nessacary
"The psychological trials of dwellers in the last times will be equal to the physical trials of the martyrs. In order to face these trials we must be living in a different world."