> had the capsule been fitted with them, it would have stayed entirely clear of the event. It'd be a rough ride, but it would have been a survivable event.

Safety isn't defined by, 'did it work out ok?', but by the risk. In this case, the outcome the parent describes is hypothetical; among other things, it assumes the emergency escape system would have worked perfectly. I assume NASA wants to evaluate the risk of the helium tanks, not the hypothetical outcome.

For example, some people have survived plane crashes; the fact that it worked out doesn't mean that the risk was acceptable.