I would certainly hope not! If the technique is used in error, it would not give correct results.<quoted text>
Yet when a technique was used in error (C14 dating of dinosaur remains) it wasn't believed.
And that has been done. In particular, we know the limiting cases of when the various techniques work. For example, C14 dating should not be used for marine organisms that get their carbon from ancient sources instead of from the air: it will give artificially old dates. C14 should not be used on samples that were exposed to radioactivity for long periods of time (especially beta radiation) and that have nitrogen sources: they will give artificially young dates. K-Ar dating should not be used in rocks that are too porous: it will give artificially young dates. No method should be used for ages that are past about 10 half-lives of the isotope being tested.I think that multiple tests should be done to confirm, either the correct dating or that one or more of the methods is faulty.
These are all common sense conditions based on the way that the methods work. They are also easy-to-check conditions to see if the method is valid or not.
And yes, within these parameters, multiple dating methods *have* been used and give consistent results.