But a central question asked by Karina van Dalen-Oskam is not being answered there: what to do about intercultural differences in acceptable rhetoric?
This is a real issue and one that goes much farther than just interpersonal communication. Some disciplines, some cultures, have traditionally had very aggressive argumentative and rhetorical approaches to research communication; others have had far less aggressive ones.
I come from Anglo-Saxon studies, for example, which used to have a very hard and aggressive tone at conferences and the like (though it has toned itself down a lot in the current generation). But I'm also in North America, which has a far less aggressive academic culture on the whole, than, I'd say, the UK, Australia, or Germany.
I think there can also often be a strong gender aspect to this: part of the lessening of the aggression of tone in Anglo-Saxon studies, I'd argue, has been a result of the sea change in gender composition of the field in the last couple of decades: apparently 2/3 of the speakers at the last ISAS meeting were women, for example (I couldn't go).
So a real question is what to suggest about handling this? If you work in a discipline or culture that values that aggressive edge, for example, you can find not being tested aggressively vaguely insulting (as my father-the-physicist used to say, the worst thing in the world is being told you're not even wrong). But if you are used to a culture that values a more supportive or deferential or indirect approach to criticism and questioning, that same approach can come across as incredibly rude and exclusionary.