When my commander, Ashaya, Soul of the Wild, was destroyed using Walk The Plank, it showed the commander went back to its zone after giving me the option, but it also showed my commander was still on the battlefield. I was soon killed afterward, but my commander still remained on the battlefield when I clicked the view the battlefield. I did not get the chance to exploit this, but I can only imagine how unfair it would be if this happened and someone exploited it to full potential.