Shoes on Hobbits?

[Reginald Hill]

I think I read in the Proloque that one "breed" of hobbits sometimes wore boots in muddy weather so maybe Bilbo had some of that blood in him. Or maybe Tolkien made an innocent mistake. Was it a sketch or a real illustration? Because if it was a sketch then it probably just slipped his mind that hobbits don't wear shoes. If it was a real illustration that he put alot of time into then that's different