Help me with a paradox

One Day i was thinking about the "Thrikoti parishuddha sila" (The ultimate version of five precepts) Let me give an example how this version works.... - You can't kill - You can't aid killing - You can't hire to kill - You can't order to kill - You can't admire / promote killing - If you can stop a killing you must stop it *These can be applied to all of the precepts...* --------------- So while i was thinking about this and this came into my mind. If i see an animal getting eaten by another animal what should i do? If i see a someone having an extramarital affair what should i do? and so on.... My question is some of these are without doubt only result in a good way but some will give suffering or pain to that person or animal so doesn't that generate bad karma for me??