But that is exactly what happened... It is kind of thing you would expect from someone with no training in the subjects.
They often fall into fallacy of self authority as well.
Well you know what they say on the internet, I can't remember the phrase now. It is something like everyone is a physicist ? I suppose that is the case when the conversation is about physics. Maybe it's something like; everyone is a phd expert on whatever they talk about.
Anyway of course it is fallacious, irrelevant and completely silly to use the claim of self expertise as any kind of justification. The whole point of experts is their ability to coherently and accurately give reasons for that which they have come to believe through their systematic interaction with the material.