Funfly,
Thanks for your remarks!
To answer your question: 99% of the time, things are standard! When things are standard, people tend to relax! People are very good ( according to research ) in doing, however, not so good in monitoring.
So, back to your question, yes, if something obvious happened at the end of a 8 to12hr flight, adrenaline would kick in and people would perform better.
If an engine failure would have occurred on mentioned flight, more than likely, All pilots would have been in an increased state of alertness, and the accident would not have occurred.
I can't speak of every one but my personal experience is that flying east from AMS I start my day between 4 and 8 pm. I have two little kids so usually I'm up at around 7 am. I bring the kids to school, doing some house chores, try to get a little sleep before I go to the airport. Start flying through the night and arrive at destination at about 7 to 12 AMS time. Most flight are with 3 pilots so we divide the flying time to get some sleep. Some times I sleep. Sometimes you are wide awake. In other words, you've flown through the night with max 3 hrs sleep. Having to perform a demanding task early in the morning!!
Once again, in my personal experience,going west is a little easier, since we start early in the morning and arrive late afternoon( body time), flying back you go through the night but at least you go to familiar Airport.
Hope this helps