Legalist are in fact Antinomians

"No man exercises evangelical repentance even in the smallest degree but he who repents of this diabolical enmity and opposition of his heart to 'the glory of God in the face of Jesus Christ.' And none has ever begun to mortify the members of the body of sin in his heart except he who is mortifying this self-righteous temper. Unbelief and a legal spirit, are the very soul or life of the body of sin. From 1 Corinthians 15:56, Mr. Ralph Erskine infers, 'The dangerous influences of legal doctrine tends to keep sinners under the law; for thus they are under the power of sin. The text says, 'The strength of sin is the law.' The legal strain, under covert of zeal for the law, has a native tendency to mar true holiness and all acceptable obedience to the law; insomuch that the greatest legalist is the greatest antinomian, or enemy to the law.' Unless the mortification of sin, therefore, begins in them, it cannot penetrate the whole body of sin." - John Colquhoun, A Treatise on the Law and the Gospel


That is right an antinomian is not only one who believes that the believer is not to obey the law as a rule of life in Christ but is one who believes that the law does not condemn and so he can live by its commands as a covenant of works without penalty.