On Oct. 26, 2012, plaintiff Andreas Moussouras, 53, a general contractor, was attempting to parallel park on Mission Street, near its intersection with 26th Street in San Francisco. At the same time, a Ford Echo operated by Grant Gordon attempted to pass Moussouras and struck the rear, left corner of Moussouras’ vehicle. Moussouras claimed an injury of the right shoulder. Moussouras sued Grant Gordon and the owner of the Ford Echo, Norman Gordon. Moussouras alleged that Grant Gordon was negligent in the operation of the Ford Echo and that Norman Gordon was vicariously liable for Grant Gordon’s actions. Grant Gordon claimed that he miscalculated the turning angle of Moussouras’ vehicle and clipped the rear, left corner bumper of Moussouras’ truck at a low speed. Thus, the Gordons conceded liability., Moussouras claimed that he sustained a full-thickness tear of the supraspinatus tendon of his dominant, right shoulder, resulting in a 3-centimeter retraction. He eventually presented to a Kaiser facility on Oct. 31, 2012, and once again in November 2012. Moussouras claimed that he initially treated with a home exercise regimen, as well as pain management care, but that he ultimately required surgery. He underwent open reduction and internal fixation on March 11, 2016, followed by a course of physical therapy. The plaintiff’s biomechanical expert opined that the mechanism of injury was that Moussouras’ right arm had been extended at the time of impact. Moussouras claimed that despite surgery, he still suffers from right shoulder pain which results in numbness that radiates into his hand. Thus, Moussouras sought recovery of $41,789 in past medical costs and an unspecified amount of non-economic damages for his past and future pain and suffering. Defense counsel disputed Moussouras’ mechanism for injury, and the causation of Moussouras’ shoulder injury and surgery. Counsel argued that Moussouras’ shoulder tear was unrelated to the rear-end collision. Specifically, counsel argued that there was insufficient force in the accident to cause Moussouras’ injury and that given factors, such as age and his career as a contractor, show that the injury was likely pre-existing. The defense’s orthopedic surgery expert testified that while surgery was appropriate, Moussouras’ injury was likely pre-existing.