It would appear that the article you referenced is indeed a copy or derivative of the web page you have pointed out to us.
Contributors to Wikipedia are instructed to respect other authors' copyrights (see <https://en.wikipedia.org/wiki/Wikipedia:Copyrights>), but it occasionally happens that a good faith contributor inserts prose found on the web under a mistaken understanding of copyright or with the belief that a paraphrase or rewording is sufficient to avoid violating the author's copyright. While this may explain what happened, it certainly does not excuse the fact that you encountered this problem on our website. I can only offer you our sincere apologies and assure you that we do all we can to ensure that such violations are repaired quickly.
The article has been edited or deleted to remove the text which was copied from the website, and the contributor has been reminded that it is not appropriate to copy text found on other websites without explicit permission.