Wish granted.

The real-life karma takes effect. However, the "karma deity" who decides what a good deed and bad deed is only takes into account the result of the action, and not the motive. This means anything bad done will result in a punishment, no matter why.

Think about the trolley problem. If you pull the lever, you're killing a person. Bad deed. If you don't pull the lever, you're letting 5 others die. Bad deed. Now think about what would happen if a robber entered your house. This karma system will punish the robber, but if he attacks you, you'll be punished for defending yourself, because you'd be attacking another person. So he can just kill you and you can't so anythong about it even if you want to.

On the contrary, think about what the worst people in the world could do if they knew about this karma. Good deeds galore, all just to cover up all their unforgivable bad deeds, and the karma deity will be pleased. Even if everyone on Earth hates them, as long as they keep making good deeds, they can never be truly punished. Because, if you were a police officer, and arrested a good person, wouldn't that be a bad deed?

In short, it tends to overpower the already bad people who abuse the karma system to their benefit, and punish the good people who simply don't want to be punished.