As part of a pre-flight brief, as well as how to operate hatches and harnesses, you should always include that you must ALWAYS vacate the aircraft by opening the door and exiting to the REAR as the propellor may be spinning, emergency vacate or not.
There's no reason to ever step off the front of the wing. This just highlights the need to brief passengers who are not familiar with aircraft.
This also highlights the fact that inexperienced PPL pilots will blindly follow the advice of instructors. I have never known anyone say not to shut an engine down soon after starting. I have seen instructors with 10s of thousands of hours do it, seen engineers do it, and do it myself. This PPL may never have read the POH, and is just going on advice given years earlier.
I'm thinking perhaps the pilot had seen the same instructor jumping out with the engine running while he sent them solo, and therefore thinks it's the norm. Perhaps I will start including this as totally unacceptable practice for passengers in my post-course brief.