Finally managed to get this one!!
For this achievement it also needs to be the FIRST shift. (You can erase data and start over when done with all the endings)
After you speak on the phone with Mr. Denver, just proceed to get the first body, bring it back to the embalment room. There will be the first event where the body moves and freaks out Rebecca.
After this you must run for the door. Your movement will slow down and you will need to force yourself to the main entrance. Once you are there, when you are able to open the door, run to the gate and click on it, its locked...so then run to your car and try to drive away, engine dead....so lastly, run towards the fence and try to climb it....also a fail...and there is the achievement popping ;)
Not sure if any point of the fence works, in my case it was around the building close to the basement door.