“It is possible that both sites are hosted on the same computer. Sabotage cannot be ruled out, but it could also be a bug in the hosting system, or an administrative error.”
That is doubtful. If the entire page had been replaced, I would say that was a possiblity, but not when only part of the page is changed.
The entire page was replaced. The main page of the Hunter site was replaced -- more accurately, intercepted -- with a splash screen with a statement on Falwell's death, with a click-through to the main page.