You don't have to be that unlucky. Discharge across your heart can stop it, no problem. It is not at all difficult for that energy to route through your chest. You were lucky.
One thing I learned as amateur EE is to always use just one hand to probe the device under test if there is any high voltage or AC involved. You put the other hand behind you so that there is no chance you create a short right through your chest.
I remember in some EE course, the prof randomly stopped in the middle of a lecture and said roughly
"Ok now that you all know this theory, I need to remind you that you should not go do your own home electrical work, because you will get ahead of yourself and die from some kind of electric shock"
The implication being:
1. You're trained, but for EE not electrician work
2. You'll think you know what to do, even if you don't it'll cloud your judgement
3. As an EE you will make enough to pay a real electrician to do your electrical work
Needless to say in the real high power EE courses (t lines, grid, etc), this wasn't even mentioned, because it was just implicitly known that all that stuff was in the realm of "Don't physically touch this stuff in the real world ever because it will kill you and it will hurt the whole time you're dying".
But there are times I have a device on my bench that is consuming 230V AC.
I have a 3kVA separation transformer set up, which makes it safer for me to work with the device (there is no potential between the DUT and the ground).
Technically, even without the transformer the residual current protection should kick in and prevent you getting killed between device and the ground. I have tested mine couple of times to check whether it works. But I somehow still feel better with a separation transformer.
But there is still the problem that I could touch different parts of the device that are at different potential and then I could get zapped this way. There is not much protection there. Solution -- If you must, don't ever touch more than one place at a time.
"I got one hand in my pocket, and the other one holding a DMM"
I was taught to use the back of my hand to avoid gripping the damn thing and never letting go.
Late edit: I've heard you can use this factoid to your advantage to avoid being eaten by an alligator or crocodile. Wrap your arms around its snout and hold on for dear life. Their jaws are strong enough to snap you in two, but not enough to force themselves open when you're holding them shut. I don't know what Step Two is, unfortunately.
The idea being that not only will you dropping the pendant disable the robot, but it will also disable if you accidentally touch energized equipment and your hand clenches, or (more likely) you panic and squeeze the controller too tightly.
https://us.idec.com/idec-us/en/USD/Safety-Components/Enablin...
step two is waiting for the aforementioned 2x4 wielder "to beat ... whatever you might be gripping/fell onto"
As my dad used to say "It's volts that jolts, but mills that kills!"
(you can survive a jolt very large voltage, but only a few milliamps across the heart can kill you)
I recommend neither though.
The problem is when the shock is not enough to stop the heart but causes it to lose sync and go into fibrillation.