Production blades under $150 all suffer from uneven blade grinds. It is largely aesthetic and affects performance very little. You also have to be pretty nearsighted to notice it - at least I am.
Good call on your part, you've learned something about knives most users don't even think about. An even, matching grind line, especially when seen on edge or from the back, is an indication of a very high standard of fit and finish - or, you just got real lucky.
Next time you find a table of knives to look through, you'll notice how many don't come very close, even in the so-called expensive lines. You practically have to pay custom prices to get good grind lines, and even then, it may not be a priority with that maker.
Don't expect matched lines very often in blades bought for pocket money, and you'll appreciate the few you do run across in your life.
