[85a middle] Gemarah: A Sheliach (an agent) must pay [regardless of what he was actually instructed to do or say], if he caused his sender a loss. For the debtor can say to him, “You were sent for my benefit, not for my detriment.”
R’ Rosner: When an agent accepts responsibility for a mission, he must act with proper logic in accordance with what would be best for whom he is trying to help.
D-E-ep Thoughts: All of us are tasked with fulfilling G-d’s commandments and being His messengers in this world. Even though we have set guidelines to follow, we are not meant to act on autopilot as mindless robots. We are blessed with brilliant brains and must use them to act accordingly and apply reason when appropriate.