@Danny413 I guess the guest was afraid to say her husband smoked pot rather than cigars, and yes, that's not right to lie, but I can sort of understand why she did it. It's great that the place was left clean and it does sound like he smoked his doobie outside, just rolled it up while sitting on the sofa, so they weren't disrespectful in that way.
One thing occurs to me- since you say they left it very clean, it's a possibility that he actually does smoke cigars and maybe they washed the ashtray and put it back where you had left it. And disposed of the remains of the cigars. You really have no way of knowing for sure. Just because they smoke pot doesn't mean he doesn't also smoke cigars.
If I were you, I would leave them a good review, indicating how clean they left it (check-out instructions followed to the letter is pretty great), maybe mentioning the later than already agreed check-out, and the lack of response to messages during the stay, and leave it at that. They don't sound to me like problem guests that hosts have to be wary of, although some social graces like thanking you for the late check-out would have been nice.
I'm a host who gets really irritated about other hosts not leaving honest reviews, so I appreciate your wanting to not mislead other hosts. I just don't think these guests warrant low stars and a critical review.
I don't see that any harm was done, other than you feeling that you were manipulated.
I know that some hosts may not agree with me.
Personally, I couldn't care less if guests smoke pot, or even cigarettes, as long as they do it safely and outside, and where the smell won't blow back into the house.