I found this in the staff notebook that lives by the door.
Apparently, a customer who was asked to leave wanted to register a complaint. The staff gave him a notebook and a pen and told him to write it down.
No indication of who the bartender was or why the person was asked to leave. No one was fired. Carry on.
UPDATE: According to a bartender at Fatso's, their establishment has a nearly identical note posted at their bar. Must be a serial complainer on the loose downtown.