Considering I never actually saw the movies when I was that young, and my knowledge of it was based primarily off the back of a Wilson cake catalog, I couldn't differentiate which one was Star Wars and Star Trek when I was very little. I was 1 when ROTJ came out, barely.Let's not jump to conclusions now. It must have been a really young kid, like Drtooth said. In fact, my brother used to think Diddy Kong was Curious George, and he was about 5 or 6 at that time!
But seriously... really little kids think EVERYONE is Elmo until they're old enough to differentiate.