It's an equivocation because it's equivocal.
The LOI and the LNC are both expressions of the same law. The first in positive form, the second in negative form. That something has to be something and that something cannot be not something are both expressing the same thing.
The LOI and the LNC are both expressions of the same law. The first in positive form, the second in negative form. That something has to be something and that something cannot be not something are both expressing the same thing.