The chair, the board or the chair's designee, pursuant to section two hundred twenty-one of this article, in making an investigation or inquiry or conducting a hearing shall not be bound by common law or statutory rules of evidence or by technical or formal rules of procedure, except as provided by this chapter; but may make such investigation or inquiry or conduct such hearing in such manner as to ascertain the substantial rights of the parties.
N.Y. Work. Comp. Law § 222