Maus almost certainly used HE to kill the T92. HE gets a reduced rating in the TK system, due to splash effects. The T92 also has a LOT less health than a Maus. If you killed a Maus from full health, that's a lot of hp damage you're doing, and adding the destruction of the tank to the formula. You also probably used AP or premium rounds, which do not get a reduced rating. If it's at the start, the Maus may have even been in the cap circle, which means penalties are increased over and above what they usually are. That doesn't even take into account any team damage you may (or may not) have done in other recent matches. So the system does work, it just didn't work in your favour. The system doesn't provide for revenge attacks, only allowing the shooting of teammates when their name turns blue.
How do you make it work in your favour? Don't shoot the green tanks. Wait for them to turn blue, and then you're free to shoot them without penalty. And maybe not even then, if they're trying to do the right thing.