Still, negligence, involuntary manslaughter. Motive is not always needed.
But a motive could have possibly existed...
A young nobody driver standing out there defiantly pointing at and calling out a famous big time professional driver?
Were words exchanged between teams prior to this? Over a radio? Face to face? Between drivers? Anything happen prior or during the race?
All these questions and more will be asked and investigated.
Lots of interviews/statements to gather.