bk

From Genesis 3:6, we know that the woman gave the man the fruit when she was eating it.  We don’t know at what point he had arrived to where she was.  It is possible he was there while the serpent spoke to the woman.  It is possible he came up while the woman mulled over whether to eat of the tree.  It is also possible that the serpent came to the woman over a period of time on occasions when the man was not there.  (That is not to say, of course, that the man should have been there and was shirking duty.) 
Since the man was not deceived, it seems he gave in because of the influence of the woman which is reflected in his response to God, “The woman…gave me of the tree, and I did eat.”
In other words, I am saying that it is not an indisputable fact that the man witnessed the serpent’s temptation of the one created to help man.
What seems relevant to me is that Satan uses whatever means is most effective to tempt an individual to sin.