Why did my ship get destroyed even though I won the battle?
In Star Trek Fleet Command, battles involve many strategic factors, including Research, Bonuses, and Officer Abilities that can temporarily enhance your ship’s stats.

If your Officers provide a temporary Hull bonus during combat, it’s possible to win the battle but still have your ship destroyed afterward. This happens because the bonus Hull points granted by the Officers only last for the duration of the battle. Once the fight ends, the temporary bonus is removed, and if your remaining Hull is below zero, your ship is destroyed.

This is intended behavior and can be strategically used to give your ship a temporary strength boost in combat. Don’t worry, your victory will still count toward missions or events as normal.