On Jan. 8, 2010, at about 2:20 a.m., plaintiff Thomas Pappas, 57, a brakeman for the Union Pacific Railroad Co., was performing work in Union Pacific Railroad’s West Colton receiving yard when two dogs from a neighboring automobile auction yard crawled under (or came through a hole in) the fence separating the two properties and chased him. Pappas was eventually able to climb onto an electrical box and call his engineer and conductor, who were a mile away, for help. Just as the crew arrived, a driver from Renzenberger transportation service approached the scene. The crew got down from the locomotive and threw ballast at the dogs, which caused them to back off. Pappas then jumped down from the box and ran for the Renzenberger van, but fell onto his hands and knees before making it to safety. He subsequently sustained to his right, dominant shoulder and right knee. Pappas sued the automobile auction yard’s owner, Master Recovery Auto Insurance Auction, for failure to control the two dogs. Pappas also sued his employer, Union Pacific Railroad Co., claiming repetitive trauma . Master Recovery denied ownership or control of the dogs, and its counsel presented evidence that the animals were “strays” on the railroad’s property. Counsel contended that the fence in question was located on the Union Pacific Railroad’s property and was not on the property line between the two parcels. Thus, Master Recovery’s counsel argued that Union Pacific Railroad had sole responsibility for the maintenance of the fence and that the condition of the fence permitted the dogs to enter the receiving yard. Counsel also presented evidence that the railroad’s failure to train its personnel and failure to respond appropriately to the incident led to Pappas’ . The Union Pacific Railroad denied there was a hole in the fence and denied the condition of the fence permitted the dogs to enter its property. It also claimed that its employees were properly trained to respond to emergencies such as this and that the response by the van driver and crew was appropriate., Shortly after the incident, Pappas was taken to urgent care at Concentra Occupational Medical Center in Los Angeles, where he was treated and released. He sustained a torn supraspinatus tendon of his right, dominant shoulder, and partial tears of the right knee’s lateral and medial menisci. On Jan. 11, 2010, Pappas underwent arthroscopic repair of the supraspinatus tendon by Dr. Kevin Ehrhart, a treating orthopedic surgeon. He then transferred his care to another treating orthopedic surgeon, Dr. Ralph Gambardella, who performed the diagnostic and operative arthroscopic menisectomies on Pappas’ right knee in 2010. After the surgeries, in 2011, Pappas returned to work for about a year. In 2012, he underwent bilateral knee replacements and enjoyed a successful recovery, but he could not return to his old job. The Union Pacific Railroad offered him the “opportunity” to return to work as a Console Herder, Yardmaster, Response Management Communications Center dispatcher, facility manager or security guard, but Pappas chose, instead, to renew his real estate broker’s license and pursue a new line of work. One of Pappas’s treating orthopedic surgeons, Gambardella, testified that the dog incident was responsible for 50 percent of Pappas’ need for the knee replacements and that the other cause was degenerative osteoarthritis. Pappas’ other treating surgeon, Ehrhart, also testified as to the knee replacement procedures, but was not allowed to opine as to causation, per the court’s ruling on defense counsel’s motion in limine to limit Pappas to one doctor on that issue. The defense’s medical expert for the Union Pacific Railroad opined that Pappas could have returned to work in his former job and that the need for the bilateral knee replacements was entirely due to the aging process and pre-existing osteoarthritis in Pappas’ knees, which had been ongoing for decades.