It could be either. There were 2.16GHz Core Duos as well as Core 2 Duos. If he purchased it new from Apple in February '07 it is most likely a Late 2006 MBP and thus indeed a Core 2 Duo but if you want to be absolutely sure get him to tell you the serial number and pop it in to this page on the right hand side (second box down):
LOL I didn't even think of that and here I was about to tell him to get the serial number by clicking on "More Info..." from the very same window where it will clearly say what processor it is running. 😱