That's incorrect. The text is in the public ___domain but it is still covered by copyright. The copyright is not enforced outside the UK at this time. It is not pedantry; one cannot claim to have written the KJV version. A work that has passed into the public ___domain, or has become publicly available, still retains copyright.
Here's a concrete example. Someone wrote a very successful book and it is protected by copyright laws. You may reproduce sections of it, but not the whole book. After X years have passed, and the book has passed into the public ___domain, you may reproduce it in full. You may not alter the work to credit yourself as the author.
Similarly, the crux of the matter is: does the Google version of the Java API constitute a derivative work that is significantly different from the Sun-Oracle version? As stated above, the UK and US do not recognize common law of copyright. So despite the fact that the Sun-Oracle APIs are publicly available, it does not allow Google to claim that the code that belonged to Sun-Oracle is free from restrictions and thus can be copied.
"It is not pedantry; one cannot claim to have written the KJV version"
Sure one can. In fact, copyright has nothing to say regarding plagiarism. US copyright only prevents the copying of a work. I could claim to have authored Star Wars, the Bible, and your post -- copyright does not provide you recourse against this so long as I do not /copy/ them.
"The text is in the public ___domain but it is still covered by copyright."
No, it is not. Text in the public ___domain is not covered by copyright according to US law. Copyright ONLY applies to copies and incorporation into derivative works in the USA.
I apologize for being contradictory but you are completely wrong on both points here.
http://en.wikipedia.org/wiki/Copyright#Public_domain
Here's a concrete example. Someone wrote a very successful book and it is protected by copyright laws. You may reproduce sections of it, but not the whole book. After X years have passed, and the book has passed into the public ___domain, you may reproduce it in full. You may not alter the work to credit yourself as the author.
Similarly, the crux of the matter is: does the Google version of the Java API constitute a derivative work that is significantly different from the Sun-Oracle version? As stated above, the UK and US do not recognize common law of copyright. So despite the fact that the Sun-Oracle APIs are publicly available, it does not allow Google to claim that the code that belonged to Sun-Oracle is free from restrictions and thus can be copied.