When Michael, Ryan, and Pam are left alone in the conference room to discuss the offer from David Wallace, David closes the conference room door, as he and Charles exit. The camera then switches to Dwight as he receives a phone call from a former client who now wishes to switch back to Dunder Mifflin because of the financial troubles with the Michael Scott paper company. Dwight gets up to rush and tell David and Charles about the financial problems before they finalize the deal. In the background you can see that the conference room is empty and the door is open, even though supposedly Michael, Ryan, and Pam are in there with the door closed to discuss the offer.
Originally there was a regular goldfish, in the next ep Michael has a black goldfish in his little tank. Response: The previous goldfish likely died between episodes.