It’s going to be expensive to resolve. How far from the mri were the disabled devices, and was there reasonable airflow to those locations? Thinking about it, there was an emi spike starting things up (missing brass?), there’s a lot of magnetic field (things like pens and keys can go mobile) and the aforementioned helium leak. Sensitive antennas and the like won’t like the emi or magnetism, and if there are also components sensitive to He…

I once screwed with a tube colour tv using a magnet and the colours were distorted in that area of the screen until I unplugged the tv and left it for a few days. Induced currents from the magnetic field or changes in the electric or magnetic fields might not be all that good for devices that run on milliamperes or less.

And somebody has to pony up a bunch of iOS devices and some He to run blind controlled experiments. I suspect that “operating in an area that could pull fillings out of teeth” voids their warranty.