MacDui is a big broad heap of rocks at the summit, no wonder he asked. I once struggled up a vast peak on Arran, and asked the folk at the top; "Is this the summit of Goatfell?" I nearly collapsed when they replied, "Oh no, that's it away up there...", pointing to a distant and far more lofty peak.
If they had grumpily demanded to know if I had any "right" to be there I would have kicked them in the couloirs....