Some similar devises and sounds, but I couldn't say that was a rip-off, and I think borrowing elements and instrumental presentation from your own previous works is more about individual style than anything else, isn't it? To draw an analogy with my own world, I've certainly used very similar characters in my cartoons over the years. almost always subconsciously, because of my particular style of drawing - but the situations and context they are used in are different each time.
I'd be more interested if you could find examples of him "ripping off" other peoples' music.