What would happen is that he would be telling the truth after he told a lie and when he told the truth but said that, then his nose would grow. But the first part would shrink then grow. It is not hard paradox to solve.
Since "now" is a single point in time, his nose would grow about 1 second later. Before you say "That means he told the truth", remember, that single point in time has passed and doesn't cover his nose growth. Thus making it a lie.