The phrase "caught red-handed" means being caught in the act of doing something wrong or illegal. However, there are many antonyms that can be used in this situation, depending on the context. You can say that someone has been "proven innocent," "cleared of charges," or "exonerated." Alternatively, if someone is caught in the act but has a justifiable reason for their actions, you may say they were "acting with good intention" or "in the right." In some cases, you may also use words like "blameless," "innocent," or "above reproach" to describe someone who is not guilty of any wrongdoing.