Hey.
Unfortunately many users who have a high reputation or have been around for a long time think that they can start plagiarising as no one would check their content because of the trust.
It has been discovered tens of times.
Many such users also think that content that they would not have gotten away with on Steemit before HardFork (like abuse, spam, farming, etc), they could publish freely on Hive thinking that the community vigilance is poor here.
Sadly, it just makes us not to trust anyone around here.

The above post is definitely not a mistake.
It is 100% plagiarism. Even if the user provided a source to the original author, it would just turn a post into plain copypasta with 100% copied and pasted writing.
Unless the user can prove to be Amie from the plagiarised source that Hivewatchers provided in their comment here.

The user has also a history of some minor plagiarism (re-writing some article found online):

@sweetpea/turn-salt-into-glue-nifty-party-trick-and-experiment