Goku Heals Cell

Before letting Gohan fight Cell, Goku gives the exhausted villain a Senzu Bean so the test will be “fair” and will draw out Gohan’s hidden power.

It is a spectacular failure of deployment discipline: the evaluator restores a dangerous system to full capability during a live, civilization-critical trial because he is confident in an unverified model of another participant.

Goku’s bet eventually helps trigger Gohan’s victory, so the scene illustrates reckless success rather than a clean failure.