If he can see you, and you're already too low, you probably won't be able to TP out on him in time. It's worth trying sometimes, but "Just TP out on him" is becoming less and less effective over the course of time. Him having a nice nuke that you stand still under also makes TP out a less viable option.
Plus usually at my MMR, people coordinate with a BS, usually having a way to stop a TP from a rupture.
I'd say the real answer is "Don't be out of position.", with "TP out on him" going into that. If you're somewhere safe, it's just him, you have enough health to TP out on him, then you TP out on him and he just wasted everything trying to kill you.