This actually happened to a gallery in Georgetown, in Washington, DC in the 1990s:
Back when there were eight galleries in Canal Square, one of the galleries had given a show to a local -- at the time "hot" artist -- who was a painter (I say "was" because I haven't heard of the dude in years).
The artist was supposed to deliver and help hang all the paintings on a Wednesday, in order to be ready for the Georgetown third Friday openings. He did show up on Wednesday with about 50% of the work, and brought some more (freshly finished) on Thursday and to the gallerist's horror, even brought some more on Friday, and even as the show was opening at 6PM, was adding the last painting touches to several of the works.
Needless to say, several of the oils were actually wet when people starting showing up. On opening night, it was crowded, and someone apparently rubbed against one of the paintings and smeared some of the oil paint.
Now the gallerist was faced with a very irate person, demanding that his suit be cleaned (it eventually had to be replaced) and with a furious artist, demanding that the gallery pay him in full for the damaged painting.
If I am to believe the gallerist, the case actually went to court, where the judge threw it out.
