Tom MacWood,
Your question about how "conflict of interest" has changed over the years is very easy to answer.
Years, if not decades, if not a century ago, a handshake took the place of a fifty page legal contract.
Men were "Men of their Word", they didn't need fifty pages of weasel words to form a binding deal, a simple handshake was sufficient.
Today, with our super-sensitivity and politically correct atmoshphere, they'd run from that arrangement for fear of a couple of dozen law suits and tremendous financial liability.