This is just my two cents on this drama, but, imo, if D&A handled the situation more professionally and with more poise, then this really could have stopped a while ago.
For example, instead of calling out NNG, D&A could have just released what chapters they had finished and then put the project on hold stating that 'another group seems to be uploading, so we will be focusing on other projects' or something & let NNG do whatever they want until NNG became bored of it. Once NNG finally stops uploading or updates cease, then they could pick it back up again at a later time. This is not the only project D&A is working on. Putting their focus on their other projects instead of throwing more oil into the fire that is this current situation could have helped lessen this drama ten fold.
Albeit, this solution is a loss for the readers and a rather time consuming one (as it's not a guarantee that NNG would stop updating soon); however, D&A is in control of what projects they choose to focus on and scanlate and how they handle these situations. IMO, how they decided to execute it was unprofessional. However, I will acknowledge that D&A are probably doing scanlations as a hobby and are not an actual business that has consequences to their actions; therefore, emotions probably played heavily in how the situation was handled. It's hard to think rationally when emotions are running high.
Though I state my opinions on how the situation was handled, I am in no way undermining the time that D&A put into their chapters. I have done translations myself and do freelance art work, so I can tell it took a lot of time and effort per chapter - which I respect a lot and am thankful for. However, it really was almost as if they were waging war through their actions. Sometimes you just have to let 'trolls' be until the situation calms down, no matter how infuriating it may be. Trying to -win- at scanlations is not a thing that is entirely possible as the notion of -winning- is subjective.