The post in question seems to be referencing the copied text as "smuggled out snippet below" so arguably Mpamaegbu was not trying to claim authorship of that text.
Yep, seems like almost everyone ignored this little detail, in which he says that he took this from someplace else. If he decides to appeal the ban, might even help to at least change permaban into signature ban (which I would like to see more often here), if not overturning it completely.
Mpamaegbu claims to not have provided a link to the source but what actually was the source? If he copied the message from steemit and forgot to put a link, then it can be considered an error. If, on the other hand, he copypasted the post from bitcointalk, then it is blatant plagiarism because his post was not translation nor quotation.
Looking at differences between those two bitcointalk topics, the one made by Mpamaegbu lacks the part about Philippines, which is not included in either Steemit article or TG post. If he was blindly plagiarizing bitcointalk post, chances are he would copy that Philippines part too, which he didn't so i think that source is that Steemit article.