i was puzzled by hamilton un-lapping from vettel. I am not sure what to think because although he had the speed, there are clearly provisions for driver about to be lapped to let the leader pass (blue flag) and to not affect the race (which he did to an extent). i think if it was attempted by some of the backburners they would have been criticized strongly.
Hamilton did set Fastest Lap on the lap he passed Vettel so that might have helped. Hard to say the fastest guy on the track was holding you up.
anyway, my question is technical: from the feed, he was using DRS, which surprised me as i thought it could only be used when fighting for position. however i looked it up and actually didn't find that anywhere. So, can driver use it to lap other drivers if all the other conditions are met? do they in fact use it for that? i never noticed, but maybe i didn't pay enough attention?
It doesn't matter the status of the car ahead of you - if you're within 1 second when you cross the DRS detection strip, you can use DRS.
Alonso did this at least twice with backmarkers, allowing them to stay just ahead of him at the DRS detection zone so he could then use his own DRS to negate Vettel's use of it, as well.