If anyone hears the sound of the Horn (The Holy Spirit/Gods messenger) but fails to heed the warning, and the sword (death) takes him away, his blood is on his own hands.

Since he had heard the sound of the Horn but failed to heed the warning, his blood is will be on his own head. If he had heeded the warning, he would have SAVED his OWN LIFE.

But if the Watchman SEES the Sword (Judgment, Punishment, Death) coming, and fails to blow the Horn (give warning thru the Scriptures on the particular matter) and the Sword takes away a LIFE,

Then that person will die in his iniquity (knowing to do right according to Scripture but chooses to do wrong via the tradition of men) BUT I the LORD will hold the Watchman accountable for his Blood. (His Death)

(Ezk 3:16-22) (Ezk 33:1-7)