Why did Armstrong trust Wargrave?

Why did Armstrong trust Wargrave? Armstrong does not suspect Wargrave, largely because of Wargrave’s place in society, and this trust reflects Armstrong’s fatal obsession with social status. He thinks that the trick of faking Wargrave’s death will confuse the murderer and flush him out into the open.

Armstrong does not suspect Wargrave, largely because of Wargrave’s place in society, and this trust reflects Armstrong’s fatal obsession with social status. He thinks that the trick of faking Wargrave’s death will confuse the murderer and flush him out into the open.