Now imagine Dusty was still around and all the subs were in the lineup spot of the player they were replacing. Oh look, some guy named Short is leading off tonight and Trammell is hitting 3rd.
It was pretty much the perfect time to do it from F1's point of view if you think about it. McLaren ended up with the exact same number of points and Lando won, so they weren't going to bitch too much about it after the race. The drivers are going to immediately stop doing it also because no one will want to risk losing a race over it.
I don't think a warning was necessary. The drivers all know it's against the rules. The safety car was having trouble staying on track in some of the corners so it wasn't a great time to play games with Max. I would say that probably contributed to him getting a 10 second penalty.
No car may be driven unnecessarily slowly, erratically or in a manner which could be deemed potentially dangerous to other drivers or any other person at any time whilst the safety car is deployed.
They had the telemetry from his car, so they had a good idea if it was enough to be considered erratic. He also did the same thing on an earlier restart.
It wouldn't shock me. He just needs a decent car to be in contention. It's pretty clear based on Laswson and Yuki's results that the Red Bull is in the bottom 3rd this year and the points finishes he gets are all because he's just that good.