Agree with one addition: when deciding the right way of proceeding we must also take into consideration, that we may not have the full set of information to carry out the decision. Situation for example: we see two men struggling on the street, we help the one who seems to be the victim, and then it appears that our “victim” was a thief who stole the second man’s wallet :) Yes, it’s an edge case, but edge cases best show the complexity of moral decision making. As you wrote, PD is and should be a general rule and a help to make the proper decision in situations without enoug information or morally ambiguous.