Interesting play in SD-STL

If the ump was pointing that the runner went out of the line he didn't sell it at all. If the runner went out of the path, why wait until the catcher and runner race to the plate? Shouldn't you call the out as soon as it occurs? I wish I could understand what you baseball guys think when you see this play -- as an outsider I see an ump who doesn't know what call to make and that looks really bad. He even asks the catcher "did you touch him?".