This is a tricky one for is pinocchio said his nose will grow and it did not it would be a lie but then his nose would grow so it would be the truth.
This controdiction could just be simply solved by his nose growing then going back to normal or it could go as far as his "body of wood" to crack until he was no longer a "real" boy. I do not think we will ever know for fact (although the "fact" would be a decision by disney)