Here is the answer I received from Rabbi Moshe Weiner of Jerusalem, author of The Divine Code, on the details of the Noahide Code:
This would not be your fault. But if your reasonable assumption is that the person will not use the money in the correct way, then you should not give him cash. If your presumption is not so, then you are giving charity to help a person. It is his own wrong if he uses it for doing harm or evil. Obviously once you know that will happen, you should stop assisting this person with cash. A Noahide should not assist another person to damage himself.
This would not be your fault. But if your reasonable assumption is that the person will not use the money in the correct way, then you should not give him cash. If your presumption is not so, then you are giving charity to help a person. It is his own wrong if he uses it for doing harm or evil. Obviously once you know that will happen, you should stop assisting this person with cash. A Noahide should not assist another person to damage himself.