Jenna Fischer revealed during an episode of the Office Ladies podcast that the original script had her vomiting on the bar, when she's drunk and sitting next to Jim. The Chili's personnel who were overseeing the production (as the episode took place at a Chili's location, albeit fictional) were concerned as to what repercussions that might have on their brand and filming shut down as
Greg Daniels and
Mindy Kaling scrambled to find an alternative to that scene - which ended up being Pam falling off the stool, and subsequently being banned from Chili's due to her disorderly behavior. The manager also explicitly clarified that Pam had been sneaking drinks and was not over served by the staff.