I still would not count out a wild yeast contamination. You would have to get a whole heck of a lot of extra priming sugar in that one bottle to get to the point of burning. A typical priming addition only raises the batch SG by a couple points.
Since the other bottles are good, it just doesn't add up. I suppose there could be a flat bottle or two in the batch, but the simpler explanation is a dirty bottle. No matter what the actual cause is, you ought to mind both your sanitation and your mixing for priming sugar.