Hey Robbie, well yes, it says "like a gyro", but with all the explanation following that statement, it is still wrong.
Directly from the Rotorcraft Flying Handbook:
Gyroscopic Precession
The spinning main rotor of a helicopter acts like a gyroscope.
As such, it has the properties of gyroscopic action, one of
which is precession. Gyroscopic precession is the resultant
action or deflection of a spinning object when a force is
applied to this object. This action occurs approximately 90°
in the direction of rotation from the point where the force
is applied (or 90° later in the rotation cycle). (And so on ...)
I am pretty sure it is 72°.