Possible.
But IMO, it could be a case-to-case basis and if you can see the (accused being plagiarized) post of Mpamaegbu, the intention could be possible is to show a reference or content that come from the online article (or somewhere else) but the big mistake is, Mpamaegbu forgot to include the link or must be quoted it from the original author, which is this is very strong evidence by suspecting of being a plagiarist.  So IMO, that could be a mistake by him by not being accredited to the original author.

There's no problem if he copied the entire content but there's a link to the original source.

Just my two sats and waiting for a best result of Mpamaegbu.