I am not a historian, but it looks like you might have gotten this backwards. I am looking at a 2014 calendar, and May 12 is actually after February 27.
The OP's post appears to actually be the one that was plagiarized.
Actually the content is quite common copied by more projects as FAQ. I have found more examples but the OPs one was posted before I agree and I already found some traces of same content in the thread listed in the post.
Someone quoted it here :
https://bitcointalk.org/index.php?topic=450381.msg5107429#msg5107429The content was probably in the OP of the post mentioned as reference and it was edited later and delete from there.
Still, I think he should have just quoted the text instead of copy pasting it directly.
The content may have been copied from the post quoted by the post you cited. However I do not think you are describing plagiarism, and it is certainly not something the OP should be banned, nor punished (by forum administration) for, as he clearly cited a source:
When it comes to plagiarizing, people will be banned when they pass off someone else's words as their own, not when they use BB code incorrectly, or make mistakes when citing the source to the extent that it is still clear there is a source, and the content is not original.