Adam's sin imputed to Eve?

One of the most bizarre teachings of CBMW is the one taught in Recovering Biblical Manhood and Womanhood in chapter 3 written by Raymond C. Ortlund Jr. Here Mr. Ortlund states that God pronounced the death sentence on Adam alone so that Eve died not because she ate of the forbidden fruit. According to Ortlund she died because of Adam’s sin. On page 110, Mr. Ortlund writes:
The fourth point here is that God told Adam alone that he would die. But Eve died, too. Why then did God pronounce the death sentence on Adam alone? Because, as the head goes, so goes the member. [emphasis mine] …