Coach is hillarious. He thinks he can debunk C-14 dating without even knowing basics like the half life of the isotope or even what beta decay is.
The life of a religious nut must be easy. No critical thinking allowed 
I have no idea what Coach said -- most is garbage I know, but any scientist worth their salt will freely acknowledge that there are issues with C-14 dating. Even simple things such as uptake rate modify the C-14 results. It's a decent baseline but most scientists and
Discovery Channel-style shows use it at a 100% accurate measurement when it's not.
That is sad because people who haven't looked into the history (why scientists use it, how they came up with it as a measuring stick, the drama and politics behind it, etc) and science of C-14 use it in their arguments and research as infallible fact and bludgeons anyone who disagrees with them with it as their beating stick. They are less interested in the truth their profess to want, and more interested in forcing people to their position....but that goes both ways and Coach is a good example of the other "side".