Don't worry he will get the required time, I believe it is 150 hours total time, that could be for the commercial though. He still has to pass the written and the instrument is the hardest one that there is. Also most of the DPE's that do the instrument check ride are a lot harder than they are on the private, the way they look at it, the guy taking the instrument is going to be trolling around in the clouds with them, and they want them to know what they are doing. The reason I know is my dad was a DPE out of the San Antonio FSDO.