After everyone else has vacated Hamunaptra, and Burns has had his face pulled apart,Benny is wondering around until he is backed up against the wall by Imotep. When he says he may have use for Benny, and shows him the gold in his hand, notice the bone connecting his thumb and index finger. It leaves a hole in his right hand. Now after the horses and Camel's and people are gone, Imotep smashes his hand up through the ground. Notice there is no hole in his hand?

It is still the same hand. I think it is because up until that moment, they had used a computer to make the mummy Imotep. But it would have been easier to use a real human hand to crash up through the ground rather than use a computer.