I was watching an episode of the Cinema Snob where he was looking at the movie "Enter The Ninja", when a particular frame jumped out at me
and I immediately thought of our resident spinning dropkicker
While this connection may seem a bit far-fetched, I would honestly recommend reading the excellent Hardcoregaming101 article "Tracing The Influence" to see just how deep and prevalent image copying has been over the history of gaming. It's that article that made me think this just might be the case. The timelines add up well enough, with Enter The Ninja coming out in 81 and Deadly Moves coming out in 92, so there was more than enough time for someone to look at these few seconds when this scene happened (The Cinema Snob video and the scene below), assume nobody would notice since the movie came out eleven years prior, and just copy it over.
and I've seen crazier images copied for game usage, such as this
turning into this
(again, I highly recommend reading the article to see more examples of this)
plus, it also answers a big question about the character, which is why he has the facial expression in the first place. Maybe someone was watching Enter the Ninja, thought Franco Nero's expression at the time was cool/intense and tried to copy it over to their character...with mixed results. Also, if you look at their faces beyond the expression, you'll see several similarities. The same mustache for one, but similar cheekbones, somewhat identical sideburns, and even similar eyebrows (notice the arch on the left eyebrow).
So yeah, just something I thought of.