Obviously it's government-ese. so hard to say, but reading the act it looks like
If it's insured, then the insurer is liable.
If it's not insured, then the owner is liable (unless it's excluded from needing insurance due to being in some government vehicles category, like military vehicles I guess.).
The owner or insurance company is not liable if someone (who isn't the owner) switched the vehicle to "autonomous mode" inappropriately . In that case that person is liable (unless they are a minor/diminished responsibility etc. then blame the parents/legal guardian).
If the manufacture is at fault due to making a faulty vehicle/software, they can still be liable/negligent/sued/arrested, but by the insurer / owner /police, not by the victim(s) of the accident.
It's not clear if the government can just not pay anything in the case of an automated government vehicle running someone down. It seems that way as there is no liability assignment in section 2 for that case, so presumably the manufacture gets directly sued by the victim in that case?
There are no mention of changes to the driving license system.
Biting the hand that feeds IT
