I agree. I don't believe for a moment that O'Connor and his friends didn't know what they had on their hands. How do you even look at a painting like that and not realize it's got to be worth something? At any rate, as you pointed out, it was his respnsibility to get the best price he could for the painting, which would definitely have meant getting it appraised. The guy's a crook and should be fined heavily for his dereliction of duty.
My question is: Are O'Connor, and his friends, professional auctioneers? If they are, then they had a responsibility to ascertain the true value of the painting. But if they were just members of the church and of the auction committee, I think they owe nothing.
If it turned out that the painting was worth say $200.00 would the church refund $3000.00? I think not.