It obviously couldn't be a real 'old VHS in my parent's attic', because of the self-pausing - I didn't even realise we were supposed to believe that part.
Interesting, isn't it, that on a
skeptics' forum people would confidently post the
wrong explanation without (apparently) subjecting their hypothesis to some simple tests. I have noticed before on this forum that, in their zeal to debunk 'woo', people will snatch at the first non-paranormal explanation that comes into their heads, however implausible, and insist it must be right (also happens in Conjuror's Corner).
I tried it once, and got all three - the star each time. That's likely to be a common result - see the
real explanation. But I wasn't satisfied with the 'tired old' statistical explanation, so did some investigating. Obviously, the first thing to find out was whether the cards were the same every time.
I wasn't thinking in terms of a 'magic' trick - hadn't noticed the 'misdirection' to get you to use an assistant - so I just assumed there was something that increased the probability of correct guesses beyond chance. The question was then: it either is or isn't using feedback from me to 'guess' my choice. Seemed likely that it was, given that (i) the elaborate setup makes it possible, and (ii) it would give the best results. If so, it had to be something to do with the mouse-click, so I tried varying everything I could about it - in particular, the length of the pause.
I did indeed get different cards - ruling out the facile statistical 'explanation'. However, I didn't notice that I was clicking in different places, so missed the crucial connection (also, as I said, I was thinking in terms of a single player, and probabilities). The only thing I could think of was that it had to do with the length of the pause - some correlation with the position of each card in the row. I wasn't happy with this (that's why I didn't post it!), but gave up as I had no more ideas - anyway, I was indeed totally wrong!
Thank you, Azrael, for getting me to waste half an hour on the fruitless attempt

.