Ha ha, you guys are too macabre.
Yes he is surely suffering from a degree of installed COPD by now and yes he is much more probable to develop some form of ca, yet there is no such indication for that.
(esp if it's only the first such episode)
Most probably it's a mild form of viral infection, they don't have the standard severe pneumonia symptoms and tend to be underestimated.
This how this case was initially described
And then they realized that it's pneumonia, which can be further complicated with some bacterial super-infection, so long the subject breaths the open cold Alps air among other ppl.
This would torture him further and combined with COPD would make recovery even longer and more prone to more dangerous complications.
So to avoid all that, they kept him in.