Gosh, never knew there was a way for the thread to come off of the spool. You learn new things everyday.
I was told, however, that you were never to sew with a bobbin thread as the top thread, because it was wound the wrong way (or the opposite way as it was wound on the spool). I know that now, but it has never stopped me and I have to say that I haven't noticed a difference. I only do this when you really need the color that is in the bobbin and you don't have anymore on the spool.