Well, it's news to me that K-Ar dating has been abandoned.
K-Ar tests fail on young rock samples because measuring techniques don't have enough resolution to accurately determine the minute amounts of Argon present. Go out 100,000 to a couple of billion years and there's no problem.
However, in the case of this article, this is all irrelevent.
The author intentionally presented false information in an effort to make his point. That's all this is about.
What was false? He submitted a rock to the lab and it came back with an old date. And he's not the only one and this isn't the only mountain where this has been done.
If you read up on the difference between radiometric dating and isochron dating, you will see that isochron dating was implemented to try to overcome the problem that you can't reliably predict the initial amount of daughter elememt. But even isochron dating is still based on an assumption of the initial ratio of daughter to daughter-daughter.
The following link and excerpt is from the extremely biased and unreliable Talk Origins site. I don't trust anything they say, but I assume you do. The link bashes a Creationist and falsely claims he must have sampled incorrectly and accuses him of lying (although he is not the only scientists to do this test and get similar results) and then the talk origin site goes on to tell on themselves with the following paragraph, admitting that scientists abandoned K-Ar in favor of isochron dating. If the Creationist was lying and K-Ar was so reliable, then why did they abandon it? Do you see why I don't trust talkorigins.com?
"2. Morris's complaints are dated in that, for the most part, geologists no longer use the K-Ar dating technique as was practiced in 1974. Instead, K-Ar dating has been largely replaced by the related 40Ar/39Ar dating technique. " - Talkorigins.com