I think it is inappropriate in an interview situation 100%. If you can’t hold your tongue on some slight discomfort or perhaps talk about in a more diplomatic w

I think it is inappropriate in an interview situation 100%. If you can’t hold your tongue on some slight discomfort or perhaps talk about in a more diplomatic way (eg not singling out the specific person but rather just stating your upset at the interview being delayed) how are you going to react if clients/customers make you uncomfortable on conference calls? Are you going to be tactful and polite, or are you going to be direct and rude to them? Obviously I don’t know the role you were going for etc. this is just an example, but I think doing this gives a bad impression that goes beyond just whether that specific person was irritated for you calling them on their lateness