First appearance of Wendy Simms, who became the DNA tech after Mia Dickerson left.
It is seen as an error that since the victim's hymen was intact she was obviously not the biological mother. It is discovered though that the victim had a C-section scar, so theoretically she still could have been the biological mother, even with an intact hymen. Making the conclusion that they should have instantly known she wasn't the biological mother incorrect and it is not an error.
Conor O'Farrell, Undersheriff Jeffrey McKeen, did appear earlier in CSI: Miami.