This is wrong. It doesn't matter WHERE or WHEN you take the exam.
The scoring is the same all over the world.
It is a fact that IMGs score lower. But that is caused by the different medical bacgrounds of IMGs and AMGs.
Another myth is that you are compared to the applicants that take the test on the same day as you. This is also wrong. If you know everything, you will get 100%, doesn't matter what other people taking the exam in the same day knew - this means - you are not disadvantaged by taking the exam in certain period (e.g. when lot of AMGs tak the exam), despite what some people in these forums say.