This is the nature of headphone measurements. They measure differently on different test rigs, and even on the same test rig if not properly positioned. This is why Amir includes this statement in every headphone review, including this one:
In short, there is no way to predict how the headphone will perform on your head. It may comply with the measured response, or it may not. For sure, egregious discrepancies in frequency response which are confirmed by multiple measurements across multiple test rigs and different reviewers which show the same thing should be believed (for example, the lack of bass in Sennheiser HD800's which have been confirmed many times both objectively and subjectively). But I would not nitpick over a few dB of discrepancy here and there, especially in the frequency extremes. It may be real, it may not be, but even if it was, it may or may not be there when you put those headphones on your head.
So it is my view that some EQ is always necessary with headphones. Some aspects of the performance (like distortion) will remain consistent head to head, so for me it is important to get a low distortion headphone so that I can EQ it to my taste.