Therefore, are isochron practices foolproof?
Within the world that is real there is nothing perfect. There are a few isochron results which are demonstrably wrong. The significance of isochron plots is a bit counter-intuitive in some instances. And you can find understood procedures which could yield an isochron age that is incorrect. Does this keep room to discard isochron dating as entirely unreliable? Not necessarily.
The big almost all isochron dating answers are according to the main-stream age and reputation for our planet.