Carbon dating and the flood
The procedures used are not necessarily in question. A stronger magnetic field deflects more cosmic rays away from the Earth. Rapid reversals during the flood year and fluctuations shortly after would have caused the field energy to drop even faster.
You can find some further good information here: The smaller the ratio, the longer the organism has been dead. The only consistent way to interpret the geological record in light of this event is to understand that fossil-bearing rocks are the result of a massive global Flood that occurred only a few thousand years ago and lasted but a year.
Anyone can observe that dead plants and animals quickly return to the dust from which they were formed Gen. Even if they cannot provide a naturalistic mechanism, they appeal to the "fact of evolution," by which they mean an interpretation of earth history with a succession of different types of plants and animals in a drama spanning hundreds of millions of years.