In the junction box you can see the cable coming out from the underside of the box this goes to the cylinder attached to the right hand side of the frame, this is the capacitor. The motor is lying on its side with the feet on the left, putting the capacitor on top off the motor. The two cores of the cable go to the correct terminals for the capacitor.That would explain why the wire tagged Z2 went out the bottom of the junction box.
And as for a brake, they are usually spring set- and disengage when the motor is powered. So a typical brake motor does not trun freely when not powered. But if the brake was damaged, as the end of that fan certainly was, it may be loose from the shaft, in which case the motor may spin freely. A picture of the inside of that shroud will explain it all.
There is no mention of a brake in the diagram or the nameplate.