No, my plants have rediculously tight internodes due to my growing method. Sometimes I wish they would stretch a tad more and shade them so they will. The plants basically store energy all day during photosynthesis and use it at night for growth.
That was also my latest suspicion, I think the safe kept things too wet and ran the plant out of oxygen. (plants take in oxygen during the dark period). Obviously this particular pheno was more sensitive because you mentioned the other plants didn't display the same drooping.
