As he mentioned towards the end of his passage, one of the differences he states is, “1. Signs are what a doctor sees, symptoms are what a patient experiences.” if i might add that when he means what a doctor “sees” also means what is smelt, felt, tasted(in rare cases of diagnosis), hear, and sees or the 5 senses. This is the difference that he is talking about when differentiating between a sign and a symptom. A simpler way to word this is that it is all observed by perspective. A fever can be felt and seen by a doctor making it a sign but it can also be a symptom do to the fact that the patient also experiences the fever. So you are right, but technically it is not a special case because there are also other symptoms/signs that fall under this category.
In November 1942, the Italian cyclist Fausto Coppi took "seven packets of amphetamine" to beat the world hour record on the track.  In 1960, the Danish rider Knud Enemark Jensen collapsed during the 100 km team time trial at the Olympic Games in Rome and died later in hospital. The autopsy showed he had taken amphetamine and another drug, Ronicol , which dilates the blood vessels. The chairman of the Dutch cycling federation, Piet van Dijk, said of Rome that "dope – whole cartloads – [were] used in such royal quantities." 
MIKE McMAHON AND JAMIE HILL have always had a taste for horses and bourbon. Both hail from
families with pedigrees in Thoroughbreds: Mike’s parents own McMahon of Saratoga Thoroughbreds while Hill’s were the co-owners of 1977 Triple Crown winner Seattle Slew. The younger generation formed McMahon & Hill Bloodstock in 2001 and less than a decade later inaugurated the racing
syndicate Bourbon Lane Stable and the pinhooking syndicate Spruce Lane. All of their runners are given names that include the word “bourbon,” so it is no shock that McMahon and Hill have also decided to get into the business of spirits.