On March 25, 2013, plaintiff Humberto Perez, a truck driver in his 40s, was driving a tractor-trailer on Interstate 15, also known as the Barstow Freeway or the Mojave Freeway, in San Bernardino, when he was rear-ended by another tractor-trailer, which was operated by Roy Taylor. Perez claimed an injury of his lower back. Perez sued Taylor and Taylor’s employer, Western Flyer Express. Perez alleged that Taylor was negligent in the operation of his tractor-trailer and that Western Flyer Express was liable for Taylor’s actions through the course and scope of his employment. Liability was not contested., Perez claimed that he sustained a herniated lumbar disc at the L5-S1 level. Shortly after the collision, he sought medical attention for pain to his lower back pain. He subsequently commenced a two-month course of chiropractic care and physical therapy. Perez then consulted with an orthopedic surgeon, who diagnosed Perez with the L5-S1 disc herniation. On Dec. 1, 2014, Perez underwent a lumbar decompression at the L5-S1 level. He then followed up with another two-month course of chiropractic care and physical therapy. Perez claimed that despite treatment, he continues to have residual lower back pain. Thus, Perez sought recovery of past medical costs and damages for his past and future pain and suffering. Defense counsel contended that Perez did not need surgery for his . Counsel also asserted that after surgery, Perez failed to follow the guidelines of his surgeon, which included more physical therapy than the amount Perez completed. In addition, defense counsel asserted that Perez returned to work shortly after surgery.