Let's presume, for the sake of the argument, that not every conversation That Guy has is slow and painful. It's far more likely that That Guy only has a problem communicating with some people than that every conversation TG has ever had looks like the one in the article.

This is a fair assumption because otherwise That Guy wouldn't bother trying to talk to anybody anymore. So TG is TG from the perspective of the Normal Person. That Guy may be a normal person from the perspective of many other people.

So my problem with this article is that That Guy's guilt is presumed. In all likelihood this fictitious That Guy expected the conversation to go like this:

    NC: “I think the new guy is really getting up to speed quickly.”

    TG: “OK, but what do you mean by quickly?”

    NC: “After the first week he hasn't interrupted me with questions every
    hour, unlike some of the previous interns.”

    TG: “Gotcha.”

Here TG discovers that what NC originally described as "getting up to speed" really meant "hasn't interrupted me in a while". And perhaps TG knows that follow up questions are needed to figure out what NC is really saying.

If NC presumes that TG is out to antagonize him then every question will be answered with a short (and unhelpful) reply until both parties are exasperated.