On August 22, 1994 Dr. Joseph de Nanassy performed an autopsy. A preliminary report was issued on September 7, 1994, but the final autopsy report was not completed until February 14, 1995. As a result, the Baumanns did not receive the autopsy report until mid-February. The delay in the completion of the autopsy report in this and a number of subsequent cases will be discussed in Chapter Nine. At the family's request, the autopsy was restricted to an internal examination of the chest and abdomen.

De Nanassy confirmed that, while the surgical repair was intact, Aric suffered from pulmonary vein stenosis. This was greater on the left side. The pathologist concluded that the pulmonary vein stenosis would not have been amenable to corrective measures. In his report, Taylor indicated that there was a tiny hole or fenestration in the patch. However, he testified that he could not identify when or how the fenestration was made, noting that in some cases, surgeons will make such a fenestration to ease pressures. The fenestration did not contribute to Aric's death.