Joe--
I was going to mention the small-grower possibility but that did not seem likely based on your description. However, as a sidenote: Pork produced by small growers--specifically and especially pastured-pig growers--use specific 'heritage' breeds like Tamworths, Berkshires, Herefords, et. al., for their superior flavor and their not bred-out ability to do very well breeding, foraging, and growing on their own, unlike the overly cross-bred pigs used on commodity farms. The meat is bolder, richer, but I would not describe it as gamey. If you ever want to give pastured-pigs a shot a guy named Greg Gunthorp in La Grange, Ind. (Gunthorp Farm , I believe), raises great pigs, perfect for a whole-pig cook. I heard that he was or is starting to sell at a farmer's market in Chicago this year, presumably cuts. It's not cheap though.
Anyway, it sounds like the ends either thawed and got warm at some point before being re-frozen (more likely) or the ends or meat did not get frozen quickly enough at the outset. When the meat was thawing the off-flavor would slowly start to permeate the rest of the meat. I have seen this occur when something warm--hot even--is squashed againt something else in a freezer or fridge when that something else wasn't chilled sufficiently yet. The part of the 'something else' gets and stay warm for too long and spoilage starts to occur. Hard to know what happened without knowing the whole flow from butchering to your purchase but it sounds to me like that is what you were tasting.