I believe that very few Witnesses leave the Organization when they just "know" things aren't right. It's too much for most people to deal with. They need time to assimilate what they're taking in.
Personally, I read Crisis of Conscience, and still didn't make the lateral move until years afterward. Somehow, I wanted to believe that either I was getting it wrong or that Jehovah would straighten matters in his due time or that my presence as an elder in the Hall would give some individuals a measure of comfort. The bottom line was I wasn't quite ready to leave the Organization that my whole family was proudly in.
I'm curious, how long did it take YOU to leave once you recognized it really wasn't "The Truth"??