well, I've done this with carbon arrows. sometimes I'll get one that misbehaves, and I'll rotate the nock 90 degrees and it'll change how the arrow flies. It could be due to some carbon arrows having inconsistent spine or tolerances or whatever, or just nock alignment issues and it likes one position over the previous. But I've witnessed it firsthand several times.

I can't say anything in that regard about aluminum arrows though. I only use them indoors, 2613's with a 300 grain point for 3 spots. If I have one that flies funny, I junk it. No toying with it. But very rarely do I get an aluminum arrow that doesn't fly true. Maybe one or 2 every couple years out of a2 or 3batches of arrows as opposed to one or 2 junkers(sometimes more)out of a dozen carbon arrows.