What specifically happened when Holden was killed in Blade Runner?

So in the scene where Leon shoots Holden, at the beginning of the movie, a stream of quick-edit chaos happens.

At first you see Leon shoot Holden under the table. The next shot shows "oil" leaking from the bullet hole of some canister, which is followed by a CLEARLY ALIVE Holden turning around rapidly and rolling away, as though he was smacked in the face with a cricket bat. The next shot shows Leon aiming at Holden, his arm now above the table somehow, within split second. He shoots Holden again, and you can see Holden flying across the room, clearly being pulled away by cables (you can see him speed up as he approaches a wall). And to top it all off, Holden crashes and breaks through the wall, as though he was shot into it from a canon.

Now, Blade Runner being a masterpiece, this scene felt like an utter mess, and didn't fit at all into the rest of the movie. So back to my original question, what happens here? Like the actions in detail. Trust me, that I have rewatched this scene, frame by frame, multiple times, and it just bugs me every time.

Fancher and People's script read something radically different. After Holden asks of Leon's mother, the script read:

    Leon looks shocked, surprised.  But the needles in
    the computer barely move.  Holden goes for the in-
    side of his coat.  But big Leon is faster.  His
    laser burns a hole the size of a nickel through
    Holden's stomach.  Unlike a bullet, a laser causes
    no impact.  It goes through Holden's shoulder and
    comes out his back, clean as a whistle.  Like a
    rag doll he falls back into the seat.  Big slow Leon
    is already walking away, but he stops, turns, and
    with a little smile of satisfaction fires through
    the back of the seat.

    As Leon walks out of the room the Voight-Kampff
    begins to blink, faint but steady.

If anyone has any idea about what is happening in the movie version of this scene, then let me know.