Nothing in this Part:
(a) prevents a person being held vicariously liable for a proportion of an apportionable claim for which another person is liable; or
(b) prevents a partner from being held severally liable with another partner for that proportion of an apportionable claim for which the other partner is liable; or
(c) affects the operation of any other Act to the extent that it imposes several liability on any person in respect of what would otherwise be an apportionable claim.