With a year in Al-Anon, I can honestly say I have never heard what your FIL told you. However, I have been encouraged by old-timers in the program to wait through the first year of my husband's recovery before doing anything drastic. But he's in AA and working the steps...
I agree with Lexie on this one. Have lots of compassion, but do what you need to do to protect yourself first and foremost.