What is the test for ordering an entire new trial in a personal injury case?

^4. A court may order an entire new trial when excessive or inadequate damages suggest liability was not clearly established and a limited retrial would be prejudicial to either party. (Liodas v. Sahadi (1977) 19 Cal.3d 278, 285-286 [partial new trial on damages prejudicial and new trial on all issues required]; Hamasaki v. Flotho (1952) 39 Cal.2d 602, 608-609 [entire new trial warranted because low verdict indicated jury compromised because liability a close question].)