The Parking Spot Escalation - S6-E9
Continuity mistake: In this episode Penny mentions she has a sister ("I remember my first bikini wax. My sister did it with duct tape and melted Crayolas"), but in future episodes she has only a brother.
Suggested correction: While her brother was the only one that came to the wedding she mentions her many other times and never said she only had a brother. She mentions her father dancing with her and her water breaking at her wedding. She asks her dad about Randall and Lisa. She also mentions her sister "accidentally" shot her husband. So while the brother is more prominent the sister is mentioned throughout.
The Parking Spot Escalation - S6-E9
Other mistake: Sheldon tries and fails to move Howard's car at the start of the episode. However if you look closely the car does roll backwards even though the handbrake is applied.
