Superman - It Must Have Been a Really Powerful Drill
When Superman screams in anger after he finds Lois dead, you can see the fillings in Christopher Reeve's teeth. So invulnerable Kryptonians on earth suffer from tooth decay?!? And how the heck did they put the fillings in?
Some might accuse you of harping on minutiae, but I think you have a great point. Might Superman have included the appearance of fillings to make the Clark Kent thing more convincing?
What else are slipups but minutiae? It just seems an odd place to toss it in. And it is hard to notice. Still, they could have done the shot without us having to see Reeves' teeth (and practically his tonsils).