Chances are your WH is not going to remember those "little" lies. It's also possible he now believes them to be the truth.
People like your WH and mine tell those lies because they are easier then telling the truth and make them look better.
You can ask them about them, but I would not judge R based on his responses.
What you really need to be concerned about are any lies NOW. If you think he is lying about something, call him on it immediately. You will never be able to rebuild trust unless you hash out anything you find suspect and find he is telling the truth.
If after hashing out something suspect you find he is lying, well then that just tells you he is unchanged doesn't it?
If he is remorseful and wants to stop lying, he won't get upset about having to hash things out.