Hugo may not reply to your message, Laszlo, as he no longer grows Mamms.
The presence of hooked spines seems to be a variable character in these Lasiacanthae plants. I don't know what dictates when a plant decides to grow hooks.
I rather suspect that this variety was named as a result of finding some plants that had hooked spines, but actually there probably were others nearby that lacked hooked spines.
I have seen both hook spined and straight spined plants growing closely together in the magallani populations and also in the stella-de-tacubaya populations. I'm doubt if DNA tests wouldn't show any difference.