If they are hidden in the wall, and the wall is sheathed... sure.
But I'm not your engineer on the job, so you might want to be sure they aren't working hard under certain load conditions.
FWIW, I try to leave them out when they get buried. Waste of effort... although, sometimes things change and you can't anticipate it during design / fabrication.
But, if the guy is just being lazy... well, then I'd almost want to make him keep them in.