I'm not sure, but it looks like the photo was taken in the early evening maybe 30 minutes to an hour before sunset. You will notice that no direct sunlight is on the tank, but there obviously is behind it. Take a look some day when you are out driving around and you will see that the lighting can do weird things as sunset approaches.
Don't get me wrong, it doesn't surprise me at all to find out that Reuters, AP, etc. are doctoring photos. I'm just not sure about this one.
Changing the contrast is not doctoring a photo. Everybody needs to calm down.
This is on the intellectual level of DU posters noticing that a sitting President has a bulge in his jacket during a debate and concluding that Karl Rove was moving his jaw muscles with electrodes.