Cats that bury their poo

I thought my cat was being so clean by burying her poo, not least because when locked in the house she pops in the toilet. Then I read that cats who bury their poo are submissive to other cats that use poo to mark their territory.
ETREMELY SURPRISED AT MY CAT!
She is so cruel with her claws when she is playing with me. Guess I must be firmer with next doors cat.