Example: Recruiter mispronounces my name. I don't say anything. This can be because:
1) I'm a coward. 2) I don't care. 3) I care and am not a coward, but think it would be petty to interrupt the conversation to point this out. 4) I'm overly practical and don't care about this kind of details. 5) I think the other person may feel bad if I correct them. 6) I accept that people make sometimes mistakes. Maybe I'll point it out if they do it 3 times or more. Etc.
Which is it? You'd have to know the person better to know.
Even if the person is just a coward, this could be based on specific traumatic experiences other persons didn't have and which affect only minimally the rest of the personality.
Same applies to thank you emails, coming late to the interview etc. With such subtle situations, you need to know _why_ somebody act the way they did, and without knowing the person, which you usually don't, when interviewing, you just can't.
These are just BS rules with which recruiters try to make their work easier. Similar to Codility & co. tests for software developers. Well, bad news, recruiting is hard. You'll have to take the time to listen to and think about your candidates.