I may be able to shed some light on kepler's question(s).
First, Ray Franz was not disfellowshipped for associating with a DF'd person. Peter Gregerson, Ray's employer after he left Bethel, was not DF'd, he had disassociated. At that time, people who DA'd were not shunned (which was nice for people in those days who came to realize they did not believe WT doctrine--don't we wish it were that way now). That year the WT organization announced a change in policy to treat DA'd people the same as DF'd people (in other words, they were thenafter to be shunned). So, Ray was DF'd for associating with his DA'd employer. That was the "technicality."
Why did they come after Ray? Here are some observations.
Notice in CoC how conspicuously absent Ray's uncle, Fredrick Franz, the WTS president at the time, is from all the proceedings against Ray. Does anyone think he didn't know what was going on with his nephew and, in imo, was the driving force of that action against Ray? The question is, why?
My fleshly younger brother, a JW elder and PO, never shunned me after I left, but kept hoping I could be persuaded to return to the fold. We covertly discussed and debated WT doctrine all the time. Not long after Ray was DF'd my brother was invited to attend the school for elders at Bethel (or wherever they held it at HQ--I think it was Bethel). That was before I knew about Ray Franz and his book. Later, after I had read CoC and had contacted Ray in letters and had exchanged some phone calls with him, I discussed him with my brother, though I did not reveal to him about the personal contact. That is when my brother told me about the experience he had back at Bethel when Albert Schroeder happened to join the group at his table at one of their meals.
The story about Ray Franz being DF'd had been in the Time magazine, and my brother asked Schroeder about it. According to what my brother told me, Schroeder said the decision to DF Ray Franz had been made before he ever left Bethel. The reason they did not DF him before he left was because in the leadership position he had held on the Governing Body, and he being almost at retirement age, leaving him little prospect for employment on the outside, the Society lawyers advised that Ray actually had grounds for a lawsuit against the organization. Therefore, the lawyers advised forcing him to resign and subsequently giving him a settlement of $10,000. If he resigned and then accepted that settlement, he could not then sue the organization. (It still amazes me that 1) Schroeder would discuss something like that with rank-and-file, and 2) that my brother would tell me, an apostate, about it--but the story does make sense.)
Not long after that, I was attending a graphics trade show in Orlando for my company and I arranged for a stop-over in Atlanta to meet the Franzes. Ray picked me up at the airport and enroute to their home I told Ray what my brother had told me, and Ray absolutely rejected the idea. He said Schroeder would never be party to anything like that. I am quite sure he changed his mind later. Now back to the question of why?
Some observations:
Uncle Frederick Franz, a man of small stature, had been regarded as Jehovah's scholar extarordinaire for many years. When his nephew, who had served faithfully as a special pioneer, missionary, and at Bethel, was invited to served on the elite Governing Body, his uncle no doubt felt there should be some measure of gratitude. Then when the younger Franz accomplished the formidable assignment of the "Aid to Bible Understanding" dictionary, it put Ray on par with the aging senior Franz for scholarship--and perhaps a test of loyalty to the organization as well, for it was in that project that Ray began to see some evidence contrary to what the WTS was teaching. That along with having been exposed to the evidence presented by Carl Olof Jonsson about the flawed WT chronology for 607BC and AD1914.
And then, Ray joined with the other members of the so-called "Governing Body" in opposing Knorr and Fred Franz in their authoritarian control, insisting on equal voting rights on the Governing Body, which was their legal right. Knorr and Fred Franz were vehemently opposed to that action, as explained in CoC. That essentially wrested absolute governing authority away from the WT president, Knorr (with F. Franz's influence). Ray was also gaining influence over leadership that was resulting in a mellowing of authority over the membership of Jehovah's Witnesses. Shunning was almost non-existent for a time. It's my opinion that at this point Fred Franz harbored growing resentment and jealousy toward his nephew, Ray. If not for Ray's influence, Fred Franz would have wielded absolute authority over Jehovah's Witnesses after Nathan Knorr died. Nevertheless, after Knorr died, Fred Franz still exercized intimidating influence over the other GB members, and in the aftermath chagrin of the 1975 debacle, he led a "house cleaning" at WT headquarters to "cleanse the organization" and Ray Franz was on his hit list. The strict shunning policy was reinstated, the word "apostate" came to the fore replacing the earlier expression of "evil slaves", DAing became a shunning offense, and the witch hunt was on. After Ray resigned and accepted the $10,000 settlement, they didn't care what excuse they used to disfellowship him in the absense of legitimate scriptural grounds.
You're probably right that if the WTS had not disfellowshipped Ray, Crisis of Conscience would never have been written. In retrospect, I imagine that the WT leadership considers it the worst mistake they ever made--I do--and if they had it to do over again, they probably wouldn't. Ray's motive for writing CoC may have been two-fold: 1) Not for revenge but for defense, as well as the events no doubt caused the "light bulb" to see things for how they really were; then the desire to confess and set matters straight. And 2) the need for an income for himself and his wife at his age.
That's my perspective.
~Binadub