It would be correct if he knew I would fold that much. Unless he had been datamining me though, he wouldn't know that. Also, I do mix it up and will call down with sometimes less than Ace high if I think someone is starting to take advantage of me. I will even raise them back.
But the point of the post is that this donk (and by extension a lot of donks) was willing to do a complete bluff cr and then follow through on the river. And this against someone he probably knew nothing about.
So if you are considering a line against an unknown donk
(like in this post from TJD) it's something to keep in mind.