Legal Alien: A Scotsman in Montreal

 
Friday Fun! Split Level this time! Updated!

Part I

Two men are working on a rooftop when all of sudden the roof gives way beneath them and they fall down an abandoned chimney. After emerging in the fireplace one man's face is completely covered in soot, and the other's is completely clean. The man with the clean face ten goes to the washroom, washeds his face whilst the man with the dirty face returns to work. Can you explain logically why this would happen?

Part II - Reworded but kudos to Doug for finding an answer to the odl one

A man builds a machine which he feeds coloured paper. The paper then emerges from the other side as $100 notes which experts cannot tell from real ones. The man then sells the machine for $50,000. How does he do it and why does he sell the machine instead of using it himself?