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."
You know, I don't know what to do on the spot when somebody shows offence at my jokes. Apologizing indicates you think you did something wrong and makes an implicit promise to change your behavior (forever!). Not something to instinctively respond with or you end up apologizing for all kinds of genuinely harmless things and people will take advantage of that.
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."