Could this be translated: "this mom is his"?
could we say : she is his mother ?
That would be היא האמא שלו.
Sounds like 'zot imah sheloa' not shelo
Why not זאת האמא שלו?
To be pedantic, האמא שלו is a bit more formal than אמא שלו, so it's a better translation to "his mother" than "his mom". But I'd accept it.
For זות - Is the audio saying "zut"? I thought it should be pronounced "zot".(?)
No, he is saying "zot".