My friend just asked if I could get her husband current (he's out of BFR and practice) so he could rent from his local school. I'm positive the school wants to check him out again, and since I'm not their employee I couldn't do it in their airplane. No big deal. But I was wondering if I could do the ground portion of his BFR, sign it off as the ground for it and have the flight school complete the flying part with his rental checkout. Or does 1 CFI have to do the entire flight review?