If the manufacturer is at fault, then the manufacturer is responsible. If Ms. Fong was at fault, then she would be responsible.
However the problem here is that the renter was at fault, but he/she is dead, so now they're trying to pin the responsibility on the closest related entity (even though with NO fault by Ms. Fong) that can also pay the costs.
If the person who died (or his/her family) has no claims to compensation from Ms. Fong, then why would the people he/she injured have any claims from her?