Aloyscious,
Have you noticed that your interesting question posed has elicited no response in 2 days? The thousands of pilots reading these pages each day willingly expose themselves to thunderstorms, icy runways, below minimums weather, engine failure in mid-ocean, terrorist attack et al, but back off from a topic which might involve political correctness, or the lack of it.
If you want definitive conclusions, take up a serious study of pure mathematics, in the area of human relationships and cultural interraction there will never be definitive conclusions.
Aviation is now a mature industry, and in it's 100 year history there are many cases of 'cultural differences' being at the root of incidents and accidents.
To the best of my knowledge (I'm no historian) there has never been a major accident arising from cultural differences in the cockpit. There was one catastrophic crash where 2 pilots of the SAME CULTURE, in observing the strictures of their own cultural norm caused the horrific crash of an Airbus in Taiwan with loss of all life. The captain, who could have averted the crash, left a worsening pitch-up situation during go-around in the hands of his co-pilot (who was relatively new to type), in deferance to the fact that the co-pilot was once his superior officer in the Air Force. Historians - please correct me.
The conclusion that I draw from the accident quoted here is not one of cultural differences being a particular problem, but one of the incompatability of certain cultural styles with safe operation of aircraft. This will happen in all cultures, a submissive to authority Asian First Officer is just as much of a problem to safety as an overly assertive Westerner from an egaletarian society. The happy, and safe, middle ground is addressed in the rules of good CRM and communication styles. CRM, and it's derivatives, is a young and imperfect 'science', and will probably always require updating as societal values and the man/machine interface change. CRM is a culture within itself, not one defined by borders, race, religion, but byaircraft safety.
Singapore is a country which has an admirable record of racial / religious / cultural harmony. This was not always so, and had to be enforced by law some decades ago. If the law were repealed tomorrow, I believe that the citizens / residents would enforce it themselves without persuasion of the law. I have lived in Singapore for 15 years in an ethnic minority, but not once felt a twinge of resentment from the good folk here, in fact, I have felt well accepted. Singapore Airlines is a real mix of nationalities / races / religions / cultures on the flight deck. The training department has been smart in correctly and sensitively addressing the problems that might arise from inappropriate cultural norms in the cockpit. A VERY senior management pilot of my acquaintance is known to give a 'right bollicking' to F/O's of his own culture, who, out of 'respect', do not correct him when he makes a mistake. The word soon spreads (the F/Os must have their own web site), and I find it very refreshing in more modern times to fly with an F/O who will speak up when needed. I note that those F/Os with their new-found freedom to disagree with authority, are no less respectful of their elders back in the normal cultural values of their home environment.
I hope that a SIA management pilot is reading this, and will correct me where necessary. I do not want to diminish the efforts of an airline that has identified a problem, and is doing it's best to get it right.
We don't have to isolate cultural differences to those of national / racial / ethnic origin. Within any society there are significant economic cultural differences. Some of the best pilots I've seen came from dirt poor backgrounds (I did). My own figuring is that if you're dirt poor, you have to learn quickly to prioritise the important over the trivial. This lends itself well to the cockpit environment. On the other side of the 'dirt poor' coin, I've also seen some of the worst of pilots, those who finally found a measure of importance and thought that a whip came along as standard equipment with the 4 gold bars.
We all have a lot to contribute to the industry, and a lot can be learned from each other if the blinkers are removed - Vive la difference!