He did gain a material advantage. Based on his positioning, he should have have to run the entire turn behind the Bahrain athlete. Plus he did take one step inside on a turn so he ran less distance
I think 'material advantage' means something different to the jury: it's not 'theoretical microscopic advantage', it's "unlikely to have affected the race outcome".
Also on the infield there is slightly more oxygen in the air so he got to inhale better air two times.