What typically happens when a sociopath works a room is that they misdirect. Being in a group that might be influenced by sociopathic behavior is often more difficult to manage - the drama/trauma/negativity is compelling and can be addictive.
Most of the socipaths that I've encountered kept in line with the "piecemeal" tactic. I pay close attention, these days, to how each individual acts, and reacts in a social setting. The boundaries remain up, and are adjusted accordingly.