Even though it has the right units, V(N002) is not across R11, therefore it is something other than impedance.
Again, think what happens when you remove all the capacitors -- which represents what happens at very low frequencies.? V and I would be in-phase, so the phase shift would be zero and can't be between -45 and -90.? If a paper suggests otherwise, either it's wrong, or being interpreted incorrectly.