Repairman’s paradox trips up engineers in biology

I’m a biologist, but for one reason or another, most of my friends ended up as engineers and programmers. As a result, I get exposed to biomedical reasoning that looks solid on its surface, but would end up causing more harm than good if taken seriously as a biohacker intervention program. Here’s one fallacy I see very often.

Let’s say you’re a local handyman. One day, you notice some shards of glass and puddles of water around your house. Something in your house broke! This is inconvenient, and you’re worried about the mold, so you