I agree that Shevell is somewhat misleading, but not nescessarily for the reason you suggest. He first defines CAS for incompressible flow (where it is the same as EAS anyway) but he does not explicitly define CAS for compressible flow, other than to state CAS is the same as EAS at sea level.
The variables by which the different speeds are related are sometimes misunderstood.
Shevell correctly implies that the relation between CAS and EAS depends on pressure altitude and Mach number.
To summarise the others:
The relation between Mach number and TAS depends on static temperature
The relation between Mach number and EAS depends on statc pressure (i.e pressure altitude)
The relation between TAS and EAS depends on density