At one point in the heyday of the EWTO, LT awarded KK 10th GM of the EWTO branch of WT. The catch was, it was only valid in the EWTO. I think it was sometime late 90's or early 00's when he actually made it an official IWTA 10, putting him on the same level as LT. I'm sure that this was political and exuberant amounts of money exchanged hands.
CCF was LT's Si-Dai under Leung Sheung. After LT left LS to finish his training with Yip Man and opened his own school, CCF became LT's student. He appointed CCF as the chief instructor of the IWTA in '82 (same year KK opened the castle) so he could travel the world spreading the gospel of WT. It was sometime in the early 00's (after '02, at least) that CCF was awarded 10th level. And you are correct, he did officially leave the IWTA with not one ill word about LT (actually, he never really told anyone why he left; my Si-Fu trains with him frequently and has asked him, and he won't say). He does still train and teach periodically at the IWTA headquarters, so he and LT must not be on as bad terms as most ex-WT guys.
When I left the EWTO side of WT and went under the Hong Kong side, my Si-Gung by way of my current Si-Fu is Tam Yiu Ming, who was a student of both CCF & LT, and Si-Hing of Chris Collins. Tam was the technical adviser of the IWTA and handled the gradings. When Tam moved to London, LT pressured him to join the EWTO and fall under KK, and Tam refused, wanting nothing to do with the EWTO organization (can you blame him?), and ended up leaving the IWTA because of this. Like CCF, Tam still often trains with LT and teaches and the IWTA HQ, but they are not officially affiliated with the organization in any way.
CCF still holds 10th level I suppose; once you've been graded and ranked, it's yours, and now CCF if Si-Jo of his own lineage of WT. Being that CCF still occasionally teaches at the IWTA HQ, I suppose his rank is still honored.
That's why LT is referred to GGM, to make sure everyone understands he's the top of the food chain, since there are 2 other people that hold equal 10th level ranking.
Check the Lineage page on my website bro, there's a lot of cool WT stuff on there.