That thread does not talk about fix sd card files attributes. With init not done, you can't do any changes on files.
Also he states that he just got sx os. He does not say that it worked before. I hate when assumptions and claims like that are made.
So, false information spreading. Hekate can't break a card. And if it has problem with hekate, he's bound to have problems with sx os payload that loads boot.dat.
(sx os payload uses a similar driver as hekate. It does not uses the switch's driver like the boot.dat code)
He also asked help through PM and I told him I had testing payloads for his case, so we can track down the incompatibility (because these sd work in Horizon and PC, so it must be a case we don't support), but I don't know if I'm willing to help now...