Facts
X., born in 1923, was the victim of a traffic accident on 30 September 1971 as a passenger on a motorcycle that collided with a car at an intersection in Zurich. He suffered serious injuries, had to receive medical treatment for years, and became largely unfit for work due to a permanent disability. X. was insured against accidents as an auxiliary worker in a printing plant. By decision of 5 August 1976, the SUVA granted him a 50% disability pension. Following the insured's claim, it recognized a degree of disability of 75%, but reduced the pension by 25% due to a pre-existing pathological condition of his thoracic and lumbar spine (Scheuermann's disease), which resulted in an annual pension of CHF 11,916.--. The owner of the car was insured for civil liability with "Zurich". The latter acknowledged that the car driver had not respected the motorcyclist's right of way and was solely responsible for the accident. It estimated the disabled person at 75% and calculated a capitalized loss of earnings of CHF 228,843.--. Due to the pre-existing spinal disease, "Zurich" also reduced its liability by 25%, therefore only wishing to compensate the victim for the loss of earnings to the tune of CHF 171,632.--. The SUVA paid the injured person a total of CHF 247,221.--, of which CHF 115,388.-- corresponded to the capitalized disability pension. It wanted to recover its benefits from "Zurich" in accordance with Art. 100 RTA, but the latter only recognized a claim of CHF 156,310.--. In July 1983, the SUVA therefore brought an action against "Zurich" to obtain the balance of CHF 90,911.-- plus 5% interest since 1 September 1977.Considerations
1. According to Art. 91 RTA, applicable in this case, the SUVA must reduce its disability benefits if external factors have aggravated it. This provision covers any pre-existing pathological condition which, without the accident, would have resulted in a lesser degree of disability, regardless of whether it had already caused pain or affected the insured's earning capacity before the accident. Due to such a pre-existing condition, the plaintiff reduced the injured person's pension by 25%. But it refuses the same right to the defendant, on the grounds that the reduction under Art. 91 RTA cannot be transposed as such to the benefits of the liable third party, who must compensate the entire damage related to the accident; the plaintiff must pay the lifelong…