I don't generally consider something connected at one end and nailed to common part of a signal circuit, but I suppose it depends on your world view. In any case, the shield shouldn't carry any signal in either topology, the noise rejection balanced systems exhibit is from the signals both floating with respect to ground, allowing them to both have similar input impedance and thus both pick up a similar amount of noise, which can then be subtracted out.

I wonder why Outlaw went to a balanced output final section? I can't see the relatively big signal and low resistance of that circuit needing noise immunity.