The simple minded WT article shows they DO NOT understand how C14 dating works. As long as a creature is alive it makes no difference if it absorbed ten tons of C14 or just a fraction of a gram. After death it decays and it is the RATIO ofC14 to decay products that establishes age. It does not "run down ever slower" as they say.
Their favourite source of science is the World Book Encyclopedia, a book for young children. It's explanation of C14 dating is seriously flawed and cannot help but make an ignorant fool writing for the cult misunderstand. I no longer have a copy, but I am sure the relevant quote can be found.