It is quite normal to feel a little out of your depth at first, particularly since there is a lot more independent study required at uni compared to school - perhaps he needs to look at some of the recommended reading or examples questions? It might just be that he is used to the more organised and controlled nature of learning at school and not aware that at university just going to lectures and doing only the essential questions/ essays etc. is not enough to be doing well.
Alternatively, it might just be that he has too high expectations of himself - the grade boundaries are a LOT lower at university to get a good grade compared to A levels, so maybe he feels like he is struggling because he only got 60% on a problems sheet, but actually this is a pretty decent grade at most universities...
However, it does sound like the main problem might be that the lecturers are rushing and not so good at explaining things. Having been in a similar position myself several times, I'd recommend:
- Talking to a student in the year above to ask if they'd had similar difficulties (sometimes it's just a bad lecturer) and if they have any recommendations
- Going through the recommended reading list and independently studying the topics he is struggling on (it is expected that students should do a certain amount of independent study at uni, and some students find that just studying the relevant topic from the textbook is actually much better than going to lectures)
- Asking his tutor/ director of studies/ course organiser/ study support dept for some advice, they may be able to give him some suggestions, speak to the lecturer about their teaching style, or assess him for any learning difficulties (which may only have come out now due to the different study methods at uni)
- Contact the lecturer with specific issues, not just "I don't understand a single thing you've taught me the past month" but "in the lecture could you possibly go over this specific topic again and explain why...".