I don't think having an 8 on verbal will definitely eliminate your chances of getting an interview at UCSF. I know someone (english as a second language) who got a 8 on the verbal section and was interviewed, then waitlisted. I think that UCSF uses a formula on for your grades, mcat, school competitiveness and your personal statement to determine whether or not you receive a secondary. Then, I think they factor in your letters, ECs, life experience and maturity to determine whether or not you receive an interview.
I can only speak for myself. I had a 9 on the verbal section, and that is not all that different from an 8. My science GPA was lower than your friends, as was my cummGPA. However, I did get an R on the writing sample, which is very different from an N. I think they look more at your personal statement to get a sense of how you write. I wound up getting an outright acceptance (though it took them months to make the decision!). I was told that I had a solid personal statement and great life experience. It seems UCSF loves the nontraditional applicant.
So, if your friend thinks that his numbers are the strongest part of his application, I'd tell him to try and improve his verbal score. However, if he has an excellent personal statement, unique life experiences, and an evident dedication to help those in need, I'd stay with the 8. A great personal statement will make the N seem invisible. But, if he is one of those people who only excels in science, then he may have trouble showing the adcom that he is a well rounded individual with strong personal traits and a good ability to communicate.
I've heard (though this is a rumor from a student at ucsf)...that they take your verbal score and multiply it by 2, and then they add your P and your B score to that. If it is 40 or above, you are sitting cool for a secondary..Of course, they also take your grades and personal statement, state residency, etc..into consideration.
Yes, an 8 is not a great score (in any category) to apply to a 'top 10 school', but to say that it will keep you from getting any love is not true. Acceptances are multifactorial. If you are great, except for the 8, I don't think it will be all that bad.