From watching the Sky coverage, it looks like they activated Double Yellow Flags for like a handful of seconds, then went Green, then Double Yellow (again for a handful of seconds) then Green.
So honestly, regardless of who it was, I think a penalty for not slowing down could be successfully argued against since the duration was so short. It was almost like the officials realized Gasly was not in danger, nor was he endangering anyone else, and it was the final hot lap of the final qualifying session to set the grid and they did not want to scupper it for those still arrears of the Checkered Flag.
Smart call by Lewis and AMG to get him out first, though, so he could not get caught out by such a situation.
So honestly, regardless of who it was, I think a penalty for not slowing down could be successfully argued against since the duration was so short. It was almost like the officials realized Gasly was not in danger, nor was he endangering anyone else, and it was the final hot lap of the final qualifying session to set the grid and they did not want to scupper it for those still arrears of the Checkered Flag.
Smart call by Lewis and AMG to get him out first, though, so he could not get caught out by such a situation.