See I know various cultures and have different ways of interacting, but at some level I just don't care.
I mean this does go to so many different racers throughout the various seasons. And I don't loathe Ron (or anything) but out of that season's cast he was the one who's behavior bothered me the most (there have been, far, far, far worse behaved racers), and the fact that Ron pretty much gave grief to so many didn't help.
For examples some people's conflicts are always internal between their team, nice to locals, and other racers. Some racers are great with their partner and assholes to locals, some are great with locals and their teammate but terrible with locals, ect, ect. But we have documented times of Ron being mean to his daughter, to fellow racers, to race judges (seriously at the time that was a first), to locals. And in most cases (except the race judge) it wasn't just an isolated case.
Like for example the Nathan & Jennifer had far more internal conflict, but it was almost all direct towards each other (even if it was about others).
I think its primarily the fact that its a parent child relationship, and that Christina did feel hurt by his words. If they normally talked that way without the other taking offense thats one thing. But she often commented on that it made her feel bad.