Continuity mistake: Before Dr. Hartman delivers Bonnie's baby, he removes a small wheelchair and places it on a cabinet next to him. After delivering the baby, he makes a funny remark about Paula Poundstone, and then he hands the baby to Bonnie. Notice that the wheelchair and the cabinet are no longer present.
Continuity mistake: As Joe is waiting on Peter, Quagmire and Cleveland at the bar, take notice that he is holding a tray with two bottles of beer on it. One bottle is sitting behind the other in the close up shot of Joe. However when the shot pans out, you see that the bottles are side by side.