I've had to ask a couple.
Of course, as you've seen with Gabriel, I've had to ask repeatedly, "If the Wright brothers were raised in a nomadic hunter-gatherer society, would they invent the airplane? If not, why not?"
This is, quite frankly, a question I think any bonehead could produce a cogent answer for. It also gets right into the heart of the matter behind inequality in scientific progress across the planet: Geniuses who do not have access to knowledge and technology will have their potential greatly stunted, regardless of any genetic advantage they may have.
Another troll I've been dueling with was an annony identified as Graeme Bird by Tom Foss. Graeme lives in denial behind fundamental concepts behind the philosophy of science such as the null hypothesis (and, by extension, falsification thereof as a basis for a positive conclusion) and burden of proof.
I repeatedly asked Graeme what the alternative method for concluding "unicorns don't exist" there is. Dodged every time.
I mean, geeze, is it that hard to humor me for a simple question that gets to the fundamentals of the matter?