LAST EDITED ON 03-07-13 AT 08:19 PM (EST)Brandon might have just thrown several people's shoes into the fire, ocean, deepest pit, etc, during his sabotage run. The show hasn't cared about destruction of personal property before this, and he may have figured that action counted as safe.
Or just not cared. That's always an option.
ETA: As for Brandon's own shoes... I can see him destroying them as well, mostly by accident. Say there had been a rainstorm, everyone was drying their things by the fire, and he scooped up an armload... But I'm deep into pure guesswork here.