During the animation of the murder, Angela says that the subclavian artery was nicked. On the images however, it is probably the carotic artery being cut, since the subclavian is much lower, passing underneath the collarbone.
When Seeley picks up the tickets from the world series you can clearly see their seat numbers; 3 and 4.
But when he looks over at the chairs he brought home in an earlier episode the camera focuses seat number 2 and 3 and fades out 1 and 4.
IF those even are the seats from the correct row.