When Stewie begins clothing himself after sleeping with the CPR baby, he has bare feet. When he slips his overalls on, he's suddenly wearing shoes.
As Peter Griffin crashed "The Peter Copter" into a tree, after the helicopter crashed sideways and damaged Joe's yard, the tree that Peter hits is no longer there.
Upon completion of their CPR class, Bruce hands each student their certification card. Meg is handed a CPR card with Peter Griffin's name on it instead of her own name.
Brian mentions that Peter Griffin has had his CPR card revoked. In actuality, CPR cards cannot be revoked. A CPR card is nothing more than a "certificate of completion", which indicates that a course of study has been completed. It is not the equivalent of a license or a certification issued by a regulatory body which legally authorizes the cardholder to perform a specialized skill (such as a driver's license or a license to practice medicine), which are indeed subject to revocation. Completion of a CPR course is not legally required for bystanders to perform CPR in emergency situations as laypersons are protected by Good Samaritan laws. It is only legally required for persons who work professionally in the field of health care, however even in the professional setting, a CPR card cannot be revoked. Peter would still be allowed to perform bystander CPR even in the absence of his card.
In the opening scene, the cast is on a boat watching the sunset over the water. However, Quahog is on the Atlantic coast and it would only be possible to watch a sunrise over the water.