It isn't a binary like that with the MRI though. If it stops strangling you in 10sec you're great, 15 you're fine, 20 you need to be woken back up.
Edit: Per the article that you have all supposedly read, he wasn't instantly incapacitated. He was pinned onto/into the machine with enough weight on him that he suffocated over seconds and ultimately died at the hospital. This would have been a "close call" with an E-stop (which they likely had, just wasn't hit soon enough).
I don't know, I imagine getting suddenly jerked across the room by your neck is not a slow and gentle strangulation event. In addition, as I understand it, currents can be induced in metal objects causing them to heat up. So no, I'm not sure that 15 seconds of violent burning strangulation of an elderly individual is fine. It's not clear this fellow died from strangulation.
Edit: Per the article that you have all supposedly read, he wasn't instantly incapacitated. He was pinned onto/into the machine with enough weight on him that he suffocated over seconds and ultimately died at the hospital. This would have been a "close call" with an E-stop (which they likely had, just wasn't hit soon enough).