I take it more like a joke from a CGI artist angry against this silly character he had to live with for months.

It's only half a second on screen, so it's not an obvious bad joke like when Jar Jar steps in poo. I mean it's so quick that you barely see it and it don't call for an audience laugh.

Lucas let it in the final cut though. So did HE think that it was really funny or did he give us a hint that he knew this character only deserves that treatment? Sadly I think I know the answer...