When paint first falls on Pauls jacket; it's just a relatively small dribble onto his shoulder and a little way down the front. When Lyle Lovett climbs down the jacket now has great deal more paint on it.
In season 3 Paul and Jamie are married by Lyle Lovett in the street and then married at their formal wedding. in season 7 - the final - they discover they are not married due to Lyle not being a licensed minister.
but they WERE married at their formal wedding.