When is a kid's temper too much?

So I went to visit my sis and while we were sitting on the couch I could heard the upstairs neighbor (maybe 11-13 years old kid) yelling at his mom "f&%$ you bit$... f&% you!" And while she's asking him to please calm down the boy immediately goes "let me leave bi$%... leave me leave or I fu@!.. you up n..word" 😐 and they both walked down stairs with the woman trying to calm him down and the boy yelling bit$%.... to his own mother from the bottom of his lungs!!! When do you seek professional help in these cases as a parent?? I cannot imagine my 7 year old talking to me that way. I don't know their story and maybe there's a lot more to understand than just to judge the boy for his rude behavior. I really don't think she will be able to get things back on track and make her kid respect her at this point. This is soo sad.. 🙁