The New York Tribune article continues:
We see by a morning cotemporary that he was confined in the House of Detention in White-street as a witness. This ought not to have been. The imprisonment of witnesses is a measure of doubtful policy at best, and though necessary occasionally to secure the punishment of crime, yet it should never be permitted unless the necessity be apparent. The discretion vested in the magistrate to demand of a witness security for his appearance beyond his own recognizance, is one that should be wisely exercised. It should not be permitted to take away the liberty of a man without some evidence that he intends to disobey the process of the courts requiring his attendance on the examination or trial of criminals against whom his testimony is regarded as material. In this case we cannot but think that injustice, however unintentional, has been done to one whose bravery demands praise rather than imprisonment at the hands of the authorities.

For a good account of William Tillman's ordeal at sea see U. S. Department of Transportation, Maritime Administration Website

From Harpers Weekly, Tillman retaking the ship.