I think the issue in the article was that someone in the group took offense and called out said speaker on his language, and the speaker just fumbled around instead of apologizing. Even a quick "Yeah, sorry," would have at least been a gesture at respect.

With the number of people and experiences out there, we're going to offend people. What matters is how we behave when we're called out.

So you're absolutely right in that "it can be a clue that the person might be generally disrespectful of others."