Unless this was an exceptionally old animal or had been browsing primarily on cedar or some type of sage it should not have an off odor as your describe.  Processing in itself may not have anything to do with the odor of the meat.  The problem you describe could be a result of how it was handled before or after it was processed.

Some of the areas to consider are:

    1) Was it a quick clean kill or did it require a lengthy tracking? 
            The longer it takes to die and the farther it travels after being shot, the more adrenaline that can react with the meat.    
    2) Was it field dressed immediately after the kill?
            In warm weather the stomach gases can start bloating and cause odor in  very short period of time.
    3) Was it gut shot or the stomach punctured when field dressing?
            Acids from the stomach along with undigested foods and fecal matter from the lower intestines and colon could cause
            contamination and off odors to penetrate the meat.
    4) Was the cavity rinsed out with clean fresh water and dried with paper towels?
            Contrary to a lot of popular opinion I have never seen clean water hurt the meat of the animal in any way, and firmly believe that they
            should be rinsed after field dressing to remove excess blood, hair, sticks, leaves, stomach juices, etc.
    5) Was it packed with ice or put in a cooler soon after harvest if the daytime temperatures were above 40 F?
             Bacterial growth take place between 40F and 140F. Hanging an animal in this temperature range hurts the quality and contributes
             to spoliage.
    6) How long was it between harvest and processing?
            In my opinion even in the controlled temperture of a meat cooler, a properly handled animal should be processed within 10 days or
            less.
     7) How was it cut? Bone-in or boneless?
            We've found that cutting wild game bone-in detracts from the eating quality by spreading the bone dust and bone marrow through
            the cuts. Have it cut boneless to maximize the eating quality.
      8) How was it wrapped and frozen?
            Double wapping with at least one of the layers being waxed freezer paper assures protection from freezer burn (drying out), and
            also guards against outside odors getting into the meat. Freezer tempertures should remain below 0 F, -10 is ideal.
       9) How was it defrosted and how long was it allowed to sit after thawing and before cooking?
              Frozen meat should be defrosted in your refrigerator and used soon after it is defrosted.

    The bottom line is that a properly handled animal should provide good eating. In many cases it's a series of errors after the trigger is pulled that causes the problem.
    You may want to marinade your cuts before cooking to help mask the odor.

Good luck,
Dave & Ruth
D & R Processing