This fellow used to actually learn languages and document the process, which was interesting. Now, however, he just tries to sell things, outsources most of his content and self-promotes. It's a pity.
That sounds a bit harsh, doesn't it? He sounds like a decent enough likable guy.
You can tell from the video he isn't rich, or anything like that, so he's just trying to make a basic living from doing what he love and what he's good at.
He didn't try to sell you up to anything in this video... The opposite of that, in fact.
So at least in this instance, this response wasn't warranted. Give him some break.
You can't put yourself in his shoes.
So you cannot tell if he is rich just from watching the video. It appears he was telling you about his modest and ordinary lifestyle that led you to believe he was not rich. That is different from your first post.
But even without lying, people can embellish the truth, especially salesmen trying to get you to buy their product. The Irish do have a reputation of being very charming and sweet talking, especially if they have kissed the Blarney stone!