think-five-whys

Runs a Five Whys root-cause trace caveat-first. It leads with the weak evidence (Card 2017 found the single-chain method oversimplifies multi-causal problems), then forces the discipline a bare why-chain lacks, namely flagging at each step whether more than one cause could apply. Use only when Five Whys is asked for by name; for any problem that might have more than one cause prefer think-issue-tree.