It doesn't look bad to me. I can't say it's the N claw. Looks a little more like overwater. Could just be something genetic about that specific one. I'd continue as planned and keep on eye on that one.
If you're inclined to do anything now, I'd mix nutes the way you plan but reserve a cup or two (whatever amount you'd pour into that one) and add 30% water to dilute the nutes. But, I wouldn't do that now. I'd wait a couple feedings to see how it progresses.
EDIT: Is it possible you got the half-strength wrong? Did you cut the mixed nutes with 50% water? Or, did you mix them separately at 50% strength? If it's the latter it's possible you didn't measure something correctly.