like i said the arguments are discussed extensively in multiple places in that paper. in this case he uses their lack of credentials to explain why they made such errors. it would be a fallacy if attacking them was all he did (and shows why twitter and decontextualized snippets are bad for any kind of in-depth arguments)

> in this case he uses their lack of credentials to explain why they made such errors

There is nothing extraordinary or wrong about people publishing articles while they "hasn't finished their Phd". Having published articles is practically required prior getting Phd. As such, it cant possibly explain anything. What Loanides is doing there is manipulating people who dont know how science works, how Phd is obtained nor know and how publishing works into thinking there is something lesser about author.

In the context of "scientific norms" this is egregiously bad behavior on Loanides side.

except he doesn't because the excerpt does not exist in the final published article. and he doesnt use twitter

Having an ad hominem alongside a different argument doesn't mean it's not an ad hominem in my book. Why not point out the errors without the additional ad hominem "explanation"?

You could -- but that's no reason to dismiss the whole paper. The linked tweet is using the ad hominem accusation to lie: the paper did address the flaws in their analysis - in fact he explains in detail why he thinks they were biased.

If you read the final paper (linked by bergstorm) it doesn't contain any of the excerpts that he screen-shotted. They probably existed in an early preprint of the paper, but they don't exist in the final paper! : https://onlinelibrary.wiley.com/doi/10.1111/eci.13554

Nowhere did I say the entire paper should be dismissed. Having an ad hominem is a smell though.