If you're involved in a road traffic accident that isn't your fault you have the right to claim back losses from the responsible party. This should not impact your no claims bounus as it was not your fault.
No claims bonuses accrued through driving a company car normally won't be valid if you change to private insurance. Unless the policy os your own and not aquired through your employer. If you currenly drive a company car and are thinking about leaving the company, then why not get some quotes today?
A fully comprehensive car insurance policy will cover any personal injuries to third parties including your passengers as well as your car and theirs, in the case of the accident being your fault, or no balme to either side.