John Gertner, "‘Elon Musk,’ by Ashlee Vance", NYT /17/2015:
He is now, quite arguably, the most successful and important entrepreneur in the world.
Matt Hutson writes:
“Arguably” is often used to temper an argument, so “quite arguably” should temper it even more. But here “quite” has the effect of strengthening the argument rather than strengthening the tempering of the argument. Seemingly paradoxically, “quite arguably” approaches the meaning of “inarguably.” In essence, by adding “quite,” we suddenly see a proposition’s being arguable in contrast to its being untenable, rather than in contrast to its being undeniable. A neat sleight of word!