At age 8 your son knows he has homework. He also knows if he has not done it. So Mom is not interested in helping him. But he can always ask you over the weekend. Obviously he is not that interested or motivated either, so I,would suggest that you check every weekend on his homework status.
All my,children had to write homework in a homework book, which, I,would check when they came home from school. I,had 3 girls. One would come home and get her work done, 1 would whine but,eventually get it done and the 3 rd would " forget " her book" on the bus. I knew my bus deliver well,had been to his house to retrieve the book on more than one occasion. Found out about homework at 7:30 on Monday. We had all the necessary resources.
My point is, your son is part of the issue here. He knows he has the homework. He is supposed to do this work on his own. If he requires the internet he needs to communicate with you that he needs it for homework. Concentrate on communicating this with him. Maybe a friendly concerned communication with Mom that son is avoiding his homework. Had you considered she might not be the culprit here?