It was probably heat or light stress from before you got it. That's not to say your lights are not too close though as well. Just be aware of that anyway. The curled leaves might not fall off, they could recover. I recently changed out my hood to a better suited hood for my grow space and for some reason the leaves on one of the top cola's curled and started to change color and look pretty bad once the new hood was in. I don't know for sure what was up with the leaves on that one cola, maybe a hot spot from the new hood, not too sure. I just raised the hood and then lowered it back to the usual height a couple days or so later and gave it some time. The leaves on that one cola recovered for the most part and everything is fine now. All the other leaves were fine through the whole thing. I'm doubting it was a hot spot but I don't know what else it could have been. Seeing how well my leaves recovered I'd like to hope that yours will too. I don't think I've ever removed a leaf that was showing signs of curling giving that taco effect. I always just corrected the light/heat issue. I'd be more concerned about the leaf that you said looked dry. Mine kind of looked a bit dry too. A different shade of green, somewhat more pale I supposed, and a bit shinny and flaky looking. I don't know how else to describe it, but it recovered.