I would be inclined to replace all those wheel nuts as you don't know what damage has been done to the others, they may also have been weakened by over tightening.
From my own experience, a lot of wheel nuts at a certain period were made of inferior materials.
Ford, Volvo, Chrysler, land Rover and Jaguar all decided to put stainless over mild steel. Yeah, great idea.
Here at LandyZone we have plenty of very knowledgable members so if you have any questions about your Land Rover or just want to connect with other Landy owners, you're in the right place.