Hundreds and thousands of malaysia worked in singapore even
before singapore became a truely independent country. Many have
since become singaporean. If we can't get along with malaysian, i
don't think we can get along with anybody else.
what you described here is most likely an isolated case of a bad
boss, a lousy supervisor, a poor manager, he can be a malaysia, a
singaporean or anybody. For there are good guys, bad guys and the
assholes among malaysian, and singaporeans. That's life and you
friends mom obviously knows it and know how to handle the
situation.
Lets not generalize because of one incident.