Coyne made the mistake of trying to respond to Coulter in kind. Her attack on evolution was rife with strawman creation and logical fallacies such as poisoning the well, she did not once address any valid scientific argument. She really had no arguments to respond to in a scientific manner that haven't been dealt with many times.
Since they are evidently so easy to address, it's a tad odd that he didn't address them, isn't it?