Maybe it was (I didnt check other airlines), but this flight always flew at least 100km to the west.
Might be weather conditions this particular day pushing all the planes north east. I have zero idea about air traffic, is there an airport doing flight control for the region that would reroute all the planes over the effing war zone because of some rain clouds?
Perhaps I can point you to the link in the comment to which you've replied which plots the courses of flights of Malaysian and other airlines from the past weeks so that you can check?!
http://graphics8.nytimes.com/newsgraphics/2014/07/17/mh17/4f...
It was a route taken by SQ ,KL and others
EDIT: oops sorry I haven't realized the labels aren't part of the image, I took it from here
http://www.nytimes.com/interactive/2014/07/17/world/europe/m...