Just listened to the ATC tape.
There is NOTHING unusal in it.
This is total professional and calm communication.
Just responding to the frequency change to HCM 120.9 with a "Good night, Malaysian 370" is typical for someone who has flown this route very often, knows the next frequency by heart anyway or/and even has predialled it in the COM set.
The only thing that is a little unusal is the repeated report to be at level 350. But these things can happen.
A terrible piece of recording knowing that a few moments later hell broke loose (one way or the other)