From the picture it looks like the string twist could have been(and probably was) causingthe problem. The serving on that string may not hold up for long even though you have corrected the direction of twist. Once loosened it's going to be weaker, so keep checking it regularly. In the future being aware of the direction to twist should prevent further problems.
A DNK string is pre-stretched and served tightly. A step the factory just doesn't have time to do at the prices they charge. The DNK string and serving will outlast a factory string many times over. With the high cost of shipping you might be wist to contact Don and see if he would be willing to ship a couple strings to you. I'm sure shipping two (or more) would save on the total cost per string. I have little experience with DNK's strings as I just started using them last year, but so far my first DNK string has more shots than most factory strings give before the serving needs attention, and the serving on his string still looks like new! I don't know what the life of the serving will be, but I'm sure his strings are the most cost-efficient strings you can buy! You should contact him and ask if he will ship to you.