No, I've been playing it the last couple of days, and gotten every possible winning combination several times (barring triple 7's, because that third's impossible to hit, but I know from experience that doesn't make it happen), and I haven't seen it. This happened way back when, when I wasn't able to win the slots 50+% of the time.
EDIT: Hmm, it worked when I got cherry-seven-seven, but it only worked once in this video:
http://youtu.be/67NZdLZ4PlUI swear it was a losing one the first time I got this, but I think it may have had the seven-seven ending as well.
A cool easter egg, nonetheless, I suppose.