Future Tense - S4-E4
Continuity mistake: During this episode, Jack injures his left shoulder playing football and has to wear a sling the entire time. Every single time Jack is shown, he is wearing a blue sling on his left arm, with the supporting strap across his right shoulder (to provide diagonal support), except once. During the party scene when Jack is talking to Dawson - the blue sling is suddenly over his right arm, with the supporting strap across his left shoulder. This scene was actually shot with the sling on the correct arm, but was "flipped" to make it fit with the direction of the next scene to follow. (00:29:45 - 00:33:40)