the two diagrams can't be about the same thing, since what is constant in the first (age disease detected) is variable in the other, and what is variable in the first (age disease contracted) is variable in the other.

Final 'variable' ought to read 'constant'.

This section,

what would you expect, should this story come to light? In a well-functioning discipline, a wave of retractations, public apologies, general embarrassment and a major re-evaluation of public health policies

is weak because many are cynical about medicine being able to do this (see Ioannidis specifically). Recommend changing 'what would you expect' to something more hopeful and acknowledging of pessimism, like "what would you at least hope, even if not expect from the field?" Or perhaps skip the "change in the field" concept and go for the jugular, "this study and the practice of citing it and believing it is killing people, and the field better recognise it and change, and if it doesn't it's gross negligence leading to thousands of deaths." Your main thrust depends on this part being impactful; as it stands it's a little weak.

The story is substantially true, but the field isn't medicine: it is software engineering.

Excellent twist, but needs to be followed up with a painstakingly simple, bare, easy to follow comparison to software engineering, preferably with a one-to-one mapping of concepts (people dying = software dying, tuberculosis = number one cause of death of software, etc) and retelling of the main story points (same syntactic structure with software engineering words instead) to solidify the analogy for people - as it stands, a not insubstantial fraction of the impact of your post is lost in translating it into software engineering, and I think it would be valuable to take that fraction down to epsilon.