Ok so I'm sure everyone is aware of the bug where sometimes some of the enemy ships in larger battles cruise along side by side with your own ships, neither side firing for awhile as they report as being out of range.
Well when this happens with a ship that has tactical repair, once the battle resumes the tactical repair ceases to function.
I had a ship with tactical repair that handily defeated many ships until I ran up against this, after the battle resumed it sat there and failed to heal at all, it instead slowly died as it pecked away at the enemy finally losing the battle by the difference of a single salvo.