Ezeediver, one caution: you may be losing out if you just work with one instructor. I wouldn't be concerned with cutting of slack OR being more difficult, any decent instructor will make sure you fulfill all the requirements, so, IF YOU GIVE IT ENOUGH TIME, you'll have a good course. And I know them perfectionist Germans, (having been one myself
), so I don't worry about that. But from my own experience, I benefited enormously by working with 3 - 4 different people. And I hadn't really wanted to, I knew the one instructor there, a sort of demi-god to me, and I wanted him, period! Imagine my surprise when it turned out that there were others there where I learned as much or more, and I came to admire them even more than the one I would have chosen originally! Little itty bitty girls, too! Assisting with yet two other instructors now, for a week, added still more tools to my arsenal. There is no one right way, and your personality plays a big role in how you do things. So the more strategies you get to observe, the more likely you are to find one that fits you well. Some things I learned (like numbering the critical elements of the skills) never sat easy with me, and it was such a relief to see that it is perfectly fine (and permissible) to do it differently.
So while I think it's perfectly ok to have a friend as your certifying instructor and mentor, I would try to get to assist, or take portions of the course, with other instructors. You wouldn't want to get all your education from reading only one book, either. No matter how thoroughly.