Yes he can use the MCAT review material for Bio, Ochem, and Gchem.
There is no physics on the DAT but they do have a math section (can use DAT or GMAT math material for this) and a Perceptual Ability section that is very specific to the DAT. Also, the Reading Comp has 3 long science passages and the questions are more content based. The reading section is way easier then the MCAT, there are no inference questions or what would the author agree/disagree with.
The science sections (bio, ochem, gchem) are all free standing question meaning there are no passages associated with them. Makes it a lot easier, but they do test evolution bio on the DAT.
Overall, having taken both the MCAT and the DAT, the DAT is much easier and it's only a 4 hour test.