Ummm... Pasteurization used to kill deadly bacteria in our food is done heating the substance to sanitize at 73-75 degree Celsius for around 15 seconds. For brewing a good coffee or tea you need a much higher temperature and I guess they don't immediately cool it down.

So, go ahead, drink your coffee or tea on the plane. Yes, it is disgusting, but it is a matter of taste, not of bacterial infection.