it’s often nitpicks (“I think one thing you said is wrong”)
I think this happens. I know I’ve done it but I’ve expressly stated my agreement with everything else but hey this one thing needs examination. I think sometimes people leave that part unsaid and maybe they forgot or maybe they just don’t have good arguments against.
Note I’m not mentioning anything else. It’s because I largely agree with what you’ve said or don’t think a counterpoint would be helpful.