Nice review, lovely ending - "...and, uh, yeah..."
That extra card you have no idea about? Looks like a matching cut card to me. Casinos using cards in single-deck games will place the deck on top of a cut card and pick the whole pile up before dealing - the cut card prevents the bottom card of the deck itself from being visible. I think it also was used in large deck shoes to function as a divider - a point at which to cease using that shoe and to move on to a new one, thus preventing card counting from being as effective.
I like that you were brief and to the point. The fact that you have a few skills with card handling doesn't hurt, either. I remember seeing 10-minute reviews for decks that were so long and so boring, I gave up two minutes in.