Authorities hack cryptocurrency seed phrase

According to the article ‘the Australian Federal Police (AFP) will allege that an analytics specialist from the AFP's Criminal Assets Confiscation Taskforce deciphered Mr Jung's cryptocurrency account's "seed phrase".’

The word ‘decipher’ is doing a lot of heavy lifting. I’m wondering if they socially engineered or just found it written somewhere in the house?

Anyway, curious as to how they did it.