Having done that though, why would you turn it back on after only an hour? Or even turn it back on at all?
Because flying with the LH AC bus off is not something you want to do if you dont have to.
In my view de-powering the bus may have been gold-plating the denial of comms scenario. Not to put to fine a point on it, an hour, maybe 80 minutes of depressurisation should have ensured it was no longer required to be un-powered.
As with you, the scenario is pure speculation on my part but this scenario is probably the simplest to explain technically. As to motive... I really can't explain it on the information available.