Russell-Hamilton collision at Spa turn 1 — whose fault was it really?

Two title-calibre drivers taking each other out (well, taking Russell out at least) at turn 1 of a Belgian Grand Prix is going to generate arguments for days. From the onboard angles I've seen it looks like a straightforward racing incident — both committed to a gap that closed — rather than either driver being obviously at fault. Russell will be livid regardless given what it cost him in the championship fight. Curious whether the stewards even looked at it twice or considered it a non-event by their standards. Anyone seen the official verdict?