Radiometric dating errors
Most likely, the effect will be dependent on the age.
I would think that the older the sample, the larger the overestimate.
However, it’s important to note that some radioactive dates (like those that come from carbon-14) don’t use the isochron method, so they aren’t affected by this particular flaw.
As a young-earth creationist, I look at this issue in a different way.
A helium balloon, for example, will deflate over time, because the helium atoms diffuse through the balloon and into the surrounding air.
A good isochron was supposed to be rock-solid evidence (pun intended) that the radioactive date is reliable. I suspect that this flaw is not the last one that will be uncovered.Their age was measured to be 6.0 /- 0.3 billion years old. Those who are committed to an ancient age for the earth currently believe that it is 4.6 billion years old.Obviously, then, the error in that measurement is 1.4 billion years, not 0.3 billion years!The isochron is supposed to take care of such issues.Essentially, rather than looking at the amounts of Rb-87 and Sr-87, we look at their compared to Sr-86.
If those rocks really have been sitting around on the moon for billions of years, I suspect that the the wide range of physical and chemical processes which occurred over that time period had a much more profound effect on the uncertainty of the age determination.