Common sense and experience tells me that cold symptoms are a pretty straightforward human response to changing environmental conditions. The nice thing with this view is that you no longer have to worry about catching a cold from someone else!
I think Karl is either arguing against the evidence or on a point of semantics.
from his own references
Can a chill cause a cold?
Folklore indicates that chilling such as getting your feet wet in winter and going out with wet hair may cause a common cold but until recently there has been no scientific research to support this idea. Recent research has demonstrated that chilling may cause the onset of common cold symptoms5. A study at the Common Cold Centre in Cardiff UK in 2005 took 90 students and chilled their feet in cold water for 20 minutes and showed that the chilled group had twice as many colds over the next 5 days as a control group of 90 students whose feet were not chilled. The authors propose that when colds are circulating in the community some persons carry the virus without symptoms and that chilling the feet causes a constriction of blood vessels in the nose and this inhibits the immune response and defences in the nose and allows the virus to replicate and cause cold symptoms. The chilled person believes they have caught a cold but in fact the virus was already present in the nose but not causing symptoms.
Also it said that the cold virus is so common amongst the population that it can be taken as given that you will be exposed to it.
So to the people experiencing it you start to suffer from a cold after you undergo an exposure to cold conditions.
Now if to an educated medical professional this is not the same thing as catching a cold due to cold conditions then let them "win the argument" even if they are completely misleading with their statement.