Jim mentions that Michael once handed out Jell-O shots at the 23rd mile of the Steamtown Marathon. The Steamtown Marathon is a real event and is an annual marathon in northeastern Pennsylvania, held the Sunday before Columbus Day.
While in the lunch room, Ryan is reading "I Hope They Serve Beer In Hell," a real autobiographical book about excessive drinking, tons of sex, and just being a humongous jerk. It's like how Ryan was in season 4.
David Wallace asks Michael for a rundown on the Buffalo clients. This is a callback to Broke (2009), featuring a subplot where Charles Miner asks Jim for a rundown of his clients, as well as Company Picnic (2009), when Michael and David announce that the DM Buffalo branch is closing.
Dwight and Toby hit some trash cans with Dwight's car. This is the second car accident Dwight is involved with on camera, the first being The Injury (2006), where he gets a concussion after hitting a pole. After hitting the trash cans, Dwight and Toby are in the office and Dwight is checking Toby for a concussion.
When Andy places the cheese cart on the "Eastern wall" of the conference room, this is accurate to the orientation of the room with respect to its windows' placement on the actual building exterior used for Dunder Mifflin.