The use of Carbon-14 for dating is not completely precise. In general, 500 years is the minimum and 50,000 years is the maximum due to the need to calibrate for background C-14 levels, and to have sufficient breakdown to establish the half-life proportions but not so much that the sample is too small to measure.
That said, they're using Carbon-14 dating on recent human remains in forensic science , although the technique works best on bodies around the 1940s to 1960s due to the increased presence of C-14 due to atomic bomb testing. Currently, the atmospheric levels of C-14 are dropping again, so the method will be less feasible for people deceased after that point.
Given the difficulty of dating samples less than 500 years old, I could readily see your friend, or the person who gave him that information, latching on to the idea of less aged items being hard to date and the actual figure involved getting enlarged with the telling.