OK. I went out and tried in my X and the loaner S. In the S, I can do this. In the X, because it's higher off of the ground, I cannot. I suspect if you're over about 6'2" or so, it might be easier/possible. It's a different geometry all around, though.
I also verified that the door will close with the same light "brake light" tap. I was wondering it required a "turn the car on" brake press, which is deeper, but that's not the case.
In the end, the door stops if it hits you either way. It's just not something you want to do in order to keep the car on. Tapping the screen is your best bet in the X.