That's why we have courts, and juries. For hundreds of years, juries have been applying the "reasonable man" standard to nuisance and real estate disputes. There is no other way to determine whether or not a particular activity is unreasonable.
In his LEASE CONTRACT, smoking cigarettes was not forbidden.
True, but there was a more general lease provision forbidding offensive odors. Unless a lease specifically prohibits a certain activity (such as having pets or smoking), then you are allowed to reasonably engage in such activity. However, a general provision in a lease banning offensive odors, sounds, activities etc. would prevent you from subjecting your neighbors to constant cigarette smoke or from owning 20 cats that stank the building up to high hell.
Just because the HOA wanted to bitch, and fine the landlord, it was the landlords obligation to protect the smokers interests.
Huh? I didn't see anything in the article about a HOA. Other tenants complained to the landlord, who decided to evict these tenants for their unreasonable activities. A jury agreed that their constant smoking violated their lease.
Whoops, I stand corrected. There is a condo board involved. It doesn't really change anything here, though. These folks violated their lease, plain and simple.