Subang Control: Malaysia three seven zero maintain three five thousand, heading zero one zero, contact Ho Chi Min at one two zero decimal niner!
MH370: three five thousand, zero one zero, good night, Malaysia three seven zero!
Whenever aircraft sign off from radio station to radio station (clearance delivery to ground to aerodrome to approach/departure to air route traffic control center) they (pilots) would say good night or good day or roger, so long. I don't see any bad sign for doing radio communications courtesy.
I think this good night will get recycled over and over until we'll forget all about the MH370.