When Archer's secretary reads aloud from the Bible, she says "Joseph" instead of "Joshua."
When the body and Bible are disinterred, the Bible is in remarkably good condition for a book which has been buried with a corpse for several years. Archer then proceeds to leaf through this valuable item in the pouring rain and in [presumably] very poor light, seemingly for the sole purpose of revealing his doings to the villains of the piece.
The feet of the hanged man are dangling about two feet higher than the chair seat on which he was presumably standing.