(1) If 2 or more persons are taken to have warranted in the terms mentioned in paragraphs 7.11.17(2)(a) and (b) or 7.11.17(3)(a) and (b), the persons are taken to have warranted jointly and severally.
(2) If 2 or more persons are liable as mentioned in paragraph 7.11.17(4)(b) or (c), or subregulation 7.11.19(3) or (4), the persons are liable jointly and severally.