I haven't smoked an Olor purito, but it seems to me like the mushroom notes do come from Olor, which Davidoff uses very frequently. Davidoff is pretty secretive about their blends, so it's also possible that it comes from one of their proprietary tobaccos, which is why it's so prevalent in their blends.
As everyone probably knows, I'm biased towards Nicaraguan tobaccos, and always have been. As you mentioned, it wasn't until Charlie mentioned the mineral notes that I started examining why... I can't say whether it's like this for everyone, but I'll try to explain exactly what it is about Dominican tobaccos.
First, it's the 'mineral' note. It reminds me of the smell that you get if you wash(or lick?) gravel. Sort of a combination of metallic and chalky. The main thing that turns me off of Dominican tobaccos(that seems to me like it's sort of unique to me), is that it weighs on my palate. What I mean by that is that regardless of the finish or the flavors, I can still 'feel' the flavors of most Dominican tobaccos on my tongue after smoking. It frequently gives me an unpleasant fatty feeling coating in my mouth, which I can sometimes still feel the next day.
I have to note that putting this into words makes me feel like kind of a crazy person.
I think the mushroom and mineral notes are two different things.
I personally have experienced the mineral quality a lot in cigars that use a lot of Dominican corojo. Tripp did a pretty good job of describing the flavor. It's kind of like the after taste you would experience if you put a rock and nickel in your mouth for a minute.
I attribute the mushroom note to old tobacco and have only really experienced it in Davidoff made cigars.
If you want to go on a flavor journey here are some cigars where people have mentioned picking up a mineral quality/flavor:
The best Dominican tobaccos (which I LOVE, and I know that makes me weird) have a very musty flavor and aroma, like musty old wood, old buildings, or old books, especially when paired with a Cameroon wrapper, which many are. This may be the "funk" you refer to - very musty like an old Lutheran church basement library. I repeat, I LOVE this flavor and aroma, and it pops up, in my experience, mostly in very nicely blended Dominican smokes. Quesada 70th and Dominican Oktoberfest were full of this, as was the Fuente Eye of the Shark, and any La Aurora Preferidos. This could very well be what you're getting.