I'm not really clued in to what's going on with gps. Way back in the day, we were one of the first companies in the area to have gps, and we'd contract out to other companies setting up control for them. I wasn't really involved with that, and setups required ~45 minutes of occupation, plus a bunch of postprocessing in the office to get usable points. There's been mobile rtk solutions for awhile, but AFAIK, they required base stations on the ground to supplement the satellites, and still couldn't get you to .01'.
All that's old stuff, and I've been uninvolved, so maybe the situation's better, but I'm skeptical. I'd have to see exactly what he's looking at, and review the documentation. The guy he was talking to mainly did property work, and that's gonna be wrong no matter what you do. A few hundredths here and there, who cares? That wouldn't work on a lot of my jobs, and there's stuff that's more exacting than what I typically do. If it truly was accurate to .01' xyz, I could live with that, but that's the upper range of tolerable error.