Yes, if you look right here:
(video at 5seconds)
it seems like the input the guy is doing has the B+G on top of the black arrow (6), and there's only 3 6 inputs, not 4. So yes, for some reason it should come out when you do it like this. But I can't help but get the feeling that the training mode inputs shown don't tell the whole story, because I continually fail to get the CS even with those kinds of input like the ones shown in the video above.
However, if you look at this guys video:
It looks like he does the input with white B+G following white 6's almost all the time (as far as I could tell). He fails at one point, which is at 1:46 and here he has the B+G on top of a black arrow (6). So it seems to me that while it _is_ possible to execute the move even if you get the black arrow with B+G on top, this is borderline fail-case and you should strive to get the B+G _after_ the last white 6. This could explain why I fail so often at it.
Hope this helps someone, and please correct me if any of you pros with a 99% success rate on CS thinks I'm on the wrong track.