This slice report stamps 'NEEDS WORK' on mobile from THREE rows — one flipped example would read 33% or 100%. Chapter 38's n-warning applies to every slice: small samples swing wildly. Fix the report to print each slice's n and to refuse a verdict when n is below 20 — print "(n=..., too small to conclude)" instead.
The break is on line 9 — but read the whole snippet first.