Just finished watching the dvr of the race. I can’t say I counted all of the top 5 DRS passes, but my rough guess is maybe 6. On none of them did the car that was passed use the DRS in the next zone or next lap to regain their position. I did see Button deploy it once after he was passed, but could not overtake.
As I suspected, most of the time the car that passes with DRS checks out, as they are the superior car anyway.
I will admit that at Shanghai, with that long straight, if the car behind deploys the DRS, the driver in front is a sitting duck.