Like I said before carbon dating goes of the rails before 1400bc in a progressive fashion. The difference between 10,000 And 20,000 years could be conceivably just 200 actual years. Truth is we do not know other than the dating is unreliable. Since we do not know how to correlate the dates to actual time we use what we get. But it leaves a potential misconception about what is really going on.
Since carbon-14 has a half life of 5,730 years, carbon dating is valid (with increasing plus or minus error ) up to about 60,000 years depending on the carbon content of the sample. Advances in mass-spect equipment has made it more accurate particularly with small samples. Have you been involved in any branch of radiometric dating?