The bar requires two basic skills.
a) know the law
b) know how to apply the law to operative fact and reach a conclusion
Knowing the law is not sufficient. You can know the law but if you write essays that are conclusory or that don't include rules or that don't apply facts or that don't have a good analysis or whatever, you won't necessarily pass. I notice you say that the friend wrote a lot of essays. I think that's a key. If you can write essays and learn from what you're writing, that's using both skills, the knowledge of the law and the application of the law to the fact pattern.
I don't think there are many people who can memorize all of the rules in the Conviser mini-review, let alone trying to memorize what's in the big outlines. The BarBri lectures will go through the "top" subjects and, for essay subjects, probably give you advise on how to write for that subject. (Each lecturer has his/her own style, but that'd be my guess.) If you can get that stuff down and have a good knowledge of the other info in the mini-review, you should be in pretty good shape.
Just as a general bar tip (and you'll hear this in BarBri), if push comes to shove and you don't remember a rule for a problem, figure out what you think the rule should be, make it up, and apply it. At that point, go for a strong analysis and hope you guessed right on the rule. After three years of law school, you're going to have a clue in a lot of areas of how things should come out. Make sure your rule works with that knowledge and that you give a complete analysis of the issue.
If you are starting to study now, or soon, for the bar, by 5 days prior to the test you should be mostly ready, anyway. If you're still trying to learn major substantive law by that point, you'll be having other issues. So, using that time for a review w/tapes is probably not all that major. Even better if you can bring an essay book and write some essays.
As long as you prepare by having most of your studying done by the time you leave, you should be fine. Make sure you don't psyche yourself out because you're not at home studying at that point. The bar is a mental exercise as much as anything else. From the stats I've heard/read about, most people don't pass or fail by all that many points. Keeping the proper attitude is as important as anything else.