In the company I work for I have many Dutch colleagues, in general I find them an absolute pleasure to work with, very professional, and they usually speak better English than I do, and I am supposedly a native speaker.
Please keep in mind that when someone is not speaking their native tongue, it is easy for their natural pronunciation or tone to make them sound harsh when that is not intended.
As to this incident, it sounds like a classic HF incident where a number of systemic problems were just waiting for the opportunity to trip someone up. Thankfully we should get a "free" lesson this time, as the biggest casualty should be bruised egos