A lot of people die every month. We're talking about a probability near-0 event where I imagine it'd be difficult to pick that deaths out from general background mortality - admittedly just based on the fact I don't recall anyone I know who needed a life-saving MRI but I know a few who died. That isn't much of a justification for a strategic helium reserve. Some level of risk just has to be tolerated, we can't afford to have a contingency for every possible hypothetical.
A lot of people die every month. We're talking about a probability near-0 event where I imagine it'd be difficult to pick that deaths out from general background mortality - admittedly just based on the fact I don't recall anyone I know who needed a life-saving MRI but I know a few who died. That isn't much of a justification for a strategic helium reserve. Some level of risk just has to be tolerated, we can't afford to have a contingency for every possible hypothetical.