I just finished watching the so-called "Ham on Nye" debate.
Overall, Nye did much better than I expected, but he still missed some opportunities. Here's one which stuck out in my mind.
Thousand-year-old wood in million-year-old basalt?
Ken Ham gave the example of some wood found encased in basalt. A creationist sent samples of each to the same lab for radiometric dating. The wood came back at roughly 40 thousand years old, and the basalt was more than 47 million years old.
Here's where Nye flubbed it: he responded by suggesting maybe the basalt "slid on top of" the wood. This weak response demonstrated he hadn't understood the problem, and Ham predictably took advantage. He correctly pointed out that the wood was encased in the basalt, which implies that the wood is older. The laboratory dates are pretty difficult to reconcile with this fact; hence, radiometric dating is unreliable. Point, Ham -- or so it doubtless seemed to the audience.
I admit I was genuinely puzzled by this one. So I googled for "wood basalt", and the first result was what appears to be the original ICR article.
I saw the flaw immediately: they dated the wood using carbon dating. Carbon-14 decays much faster than 47 million years; Wikipedia gives the upper limits of accuracy as around 45,000 years. No competent scientist would ever use this method for wood that old!
It's like using a ruler to measure the length of a road, and reporting that it's 12 inches long. Carbon dating on that sample basically pegs the meter.
Live debate sucks
Notice how strong Ham's point appeared during the debate, but how weak it turned out to be when subjected to scrutiny. The whole experiment was a fundamentally dishonest "gotcha", tailor-made to be trotted out in live debates where neither the audience nor the opponent knows the backstory.
The moral of this story is that live debate is a terrible format for people actually interested in finding out what's true.