No, as long as the stitches didn't tear he will be just fine. There is no danger in exercise or physical activity after a Mohs surgery, as long as you keep from pulling on the stitches. So, assuming those are still intact, he's just fine.
The danger of heavy lifting after Mohs surgery is formation of a hematoma. If excessive bleeding or swelling did not take place, he should be OK. In general, after dermatologic surgery on the face, avoid bending the head down to pick anything up and do not strain to the point where you find yourself having to hold your breath.