Well the answer to this question is quite simple:
On track – it´s Lewis Hamilton. Because there are some simple unwritten rules in motorsport. 1.) Don´t take your teammate out. 2.) Don´t take the race leader out. 3.) Don´t take the championship leader out. So the accident in Spielberg reads like this: Lewis Hamilton took his teammate, who was also the race and championship leader out. End of story.
99% of the blame goes out to the Mercedes management (so we have 1% left for Lewis which is pretty fair I think) – in person Toto Wolff (and Niki Lauda too). Why ? Because they failed to make an important decision at a point in the race where everything was still okay. And I can only repeat here what Jackie Stewart advised: “Hold your positions.” That´s the call. Nothing else. And you know why ? For the company. For the success of the whole F1 race team. For everbody. Nico would have won the race, Lewis would have come 2nd and the points for the team in the constructors championship would have been maxed. It would have been the best decision to take and it would have been the only one reasonable. But instead they just did nothing.
And that leads me to an important point. A company has a management to take decisions. Important decisions. Unpopular decisions. Hard decisions. That´s the only reason management exists. Everything else runs pretty fine without management. And if it fails in doing so then it has to be replaced. As simple as that.
You can´t blame your workers for doing something wrong after 50 something laps out on the track at 300km/h always hard on the edge. Lewis and Nico did their absolute best in this race. They did exactly what they are being paid for. Toto´s job would have been to max their performance for the best of the company. And he didn´t do that.
But in the end the drivers got a “last warning” and might face consequences in case of another accident. Suspension (not the part of the car).
Are you fucking kiding me ? You really want to suspend the 2 guys who did a perfect job ? That´s a typicial case of management failure. The old story – better decide nothing, than decide something unpopular. Let the workers sort this out. And if they can´t well, we can fire them. Or suspend them.