Yes, for the "propeller stopping" part, but they also mention "playing with the cool effects", and since mobile phones almost universally have rolling shutters, it's likely they did see it.

While in the video you linked it's very clear that it's a non-rolling shutter, which makes sense since most consumer-level cameras with video and that level of zoom use CCD sensors with electronic shutters, whether it's a camcorder or a " superzoom" camera.

Edit: since helicopter rotors turn much slower than propellers, you get a less cool effect of just bending the blades like in this picture: https://i.imgur.com/phTJtCd.jpg