@reginos: your explanation is perfectly plausible. But I think you underestimate how calculating and premeditated Rosberg is. He pre-planned what happened in Monaco. He got his banker lap and then stopped Hamilton getting his lap. Today, he pre-planned that, if Hamilton beats me off the line, then I need to get him before Hamilton disappears out of reach.
Rosberg turned in on Hamilton (while his car was half way alongside) and he turned away (since any collision would be very damaging to Rosberg's car). But then as Hamilton pulled ahead, Rosberg turned in again just catching Hamilton's rear left tyre with his front wing endplate.
Rosberg knew that a puncture would ruin Hamilton's race whereas the damage he would suffer would be small and easily fixed with a front wing replacement at the first pitstop.
F1 drivers are fiercely competitive. Such actions are not beyond them when winning a championship is at stake.
--
997.1 C2S GT Silver/Cocoa, -20mm/LSD, PSE, short shifter, SportDesign rims, Zuffenhausen pickup, BMW Z4 2.5i Roadster Sterling Grey/Red