Well, without a sequence parameter, you're going to find that the reference frame is right at the beginning of your animation and you wouldn't be able to tell if it was there for the right reasons or the wrong reasons, so I'm inclined to agree that it won't show up if you only have the one sequence.
However, with a sequence extracted from the middle or end of the original animation, the reference frame shouldn't be there at all. Yet it is.
However, with a sequence extracted from the middle or end of the original animation, the reference frame shouldn't be there at all. Yet it is.