Later in the episode, as Lucas and Micah walk toward the saloon, we can see this different store is on the same side of the street as the saloon. (Hattie’s—and later Milly’s—store was directly across from the saloon)
In the scene after that (see blooper page 7), the tie’s sticking out again—when everyone has the heavy coats on and the wide shots including Mark after he enters the auction barn the first time. But in his close up it’s fixed again. Then when Lucas and Micah enter the livery stable to interrupt the auction, Mark’s tie is sticking out in the wide shots. But not in the close ups. Then it’s fixed for the rest of the episode. Thanks Ann Marie for this page of bloopers!