So Jon Stewart showed his viewers last night that Glenn Beck is either a liar, or stupid, or perhaps both (why choose?). This is the same phenomenon, however, that anyone dealing with right-wingers has to deal with. Accusations and claims that are outrageously wrong, easily disproved, or are otherwise contrary to facts persist regardless of their having been disproved. This is agnotology in action.
At some point, one needs to simply call it out, then move on. I realize this isn't always comfortable, or fun, to realize one is conversing with someone who insists that what is not actually is (for myself, I have started to wonder how it is possible to function in day-to-day life when holding on to notions that are contrary to simple, easily verified fact). So, Beck's claim that his was the only news outlet to show some footage of the Israeli raid on the Turkish aid flotilla, easily shown to be outrageously wrong, will persist in the minds of far too many people. No amount of "debunking", fact-checking, what have you, will dislodge it.