That is really a weird way of wiring things up. Notice the 'output' of the power amp is tied to chassis ground. Then the speaker is tied between chassis ground the the power supply common. IOW, the 'hot' side of the speaker out is connected to the chassis instead of the 'cold' side.

In any case, the resistor is indeed part of the Zobel network.

Caution is needed because the two "ground" symbols are DIFFERENT, and on a circuit board that is a cheating way of tying things together, but not always a ground. So perhaps that capacitor in series is also suspect, possibly of breaking down under higher voltage but not staying short circuited.
AND, after an additional examination, I see at least FIVE Different "ground" symbols on the schematic drawing.That means that there are isolated networks that are not connected to each other except where they are shown to connect.
What great way to confuse anybody who may want to service this package!

 

But then there is the clicking noise. Could that be causing excess current in the network?

The clicking noise could be bursts of ultrasonic oscillation. Weird things can happen in circuits some times. If a bypass capacitor fails open then really strange things can start happening. Or if solder joints fail. And the sneakiest bug was a broken PCB trace. And with a total of FIVE different ground symbols it is easy to get a bit lost in tracing out how the things actually are connected.