Accademic offense

Hi!
My friend has a problem and I'm trying to help. He is doing a Computer Science degree and is in his last year.

During his first year he had an assignment. He and a friend from the same course discussed methods to solve it and decided to follow the same method. He finished the assignment after a few days from when it was given.
After a while the friend came asking for help with a certain part of the code. My friend showed him his code and told him he can use it as 'inspiration' but to change it so that they wouldn't get in trouble. The guy just copied that portion without changing and also gave his whole assignment to a group of other students who just copied everything (I know, stupid).
They were all accused of plagiarism, even my friend, whose code was found to be similar only to an extent of 8%. He was given a mark of 0 and the story ended.

Now he is in his third year, he is an exceptional student, promising chances of finishing with a first, masters/phd offers, job offers, most professors like him, colleagues look up to him, you get the picture.

He handed in his final year project, his professor was happy with it, got a grade over 70% (knowing from unofficial sources). Media platform project, 50pg logbook, 50pg written work of the project.

And here is the problem.
Last page or even less was taken from another source and mistakenly he forgot to acknowledge it, it was not something relevant, his professor actually said it would have been better for him to not include it.
Now he is facing another academic offense, all his work marked 0% or 30% the most (best case scenario) or even expulsion (worst case scenario).

Has anyone else been confronted with this kind of a problem? Please help with an advice.