It's perfectly possible that there's a camera or voice recorder in the bag. (I usually have a voice recorder in my pocket, or in my bag, and I've also got a 'spy' camera hidden in a pen which I occasionally use).
However I can't see why the person you refer to would want to carry a camera or voice recorder when going to the dustbin. It's far more likely that they've received threats (possibly relating to the incident you refer to?) and that they're carrying some form of weapon with them whenever they're outside.