[Repeating quote] When dealing with rocks half a billion years old, it’s impossible to resolve times to less than 5 to 10 million years ... in other words, the explosion of animal life could have happened in an instant [snip].
I can't find this quote on the internet. It would help if you would cite Coulter's source for this assertion.
The quote itself makes no sense at face value. If it is intended to mean that errors of five million years out of 500 million years will occur in dating rocks, I'd have to agree. But if errors of one or two percent are accepted, then one cannot assert that the explosion took place in a "mere" ten million years, because that would be within the value of noise.
Nevertheless, it is good to hear you discussing ages in hundreds of millions of years.