Last winter I was in a part of town where I seldom visit. The store which I was going to visit, was on the other side of the street, and I made a U turn to get to a free parking spot there. An overzealous policeman was going to give me a ticket for “crossing a double yellow line”. Except that the street was completely covered with snow and no double yellow line was visible!
I apologized, but stated that I cound not see any line and asked the officer to see for himself. He backtracked and said I made “an honest mistake”, and went on his way without giving me a ticket.
In all cases, be polite, don’t lose your cool and apologize if necessary.