He gave enough detail that a little imprecision is fine. Garrot might have a longer stride but he knows he's looking for running water. The water makes sound so even if he doesn't see it, he can follow his ears to get back on track. It's a perfectly reasonable way to navigate as far as he's concerned. It's how he's done it his entire life, and he's a little rustled that this dumb man seems to have disregarded his directions. Still, he can't expect these city folk to know anything about anything important, so he's not exactly surprised.

《You can shout. If you get really lost, I'll keep this thing close by. When do you want to do this?》