Cooking Potatoes in a crock pot-please help!

I started a roast about 2-3 hours ago. My husband told me to put a little water on the bottom, add the roast meat, and surround it/cover it with cut potatoes. The potatoes are brown "dirt" potatoes (that's what he called them). I checked the roast a second ago, and there are darkish brown spots on the potatoes on the top of the roast. Should I be concerned? I have absolutely no experience with crock pot cooking and don't want to be eating spoiled potatoes! The potatoes were fine when I cut them, and the crock pot setting was set on low, I just bumped it up to high. Please help!
Thank you!
Nikkles83