When I say that these are conspiracy theories, I guess I'm saying that I don't intend to convince anyone. I mostly just provided them for entertainment value. To my knowledge only the first has ever had widespread interest, and does potentially explain some of the odd circumstances around the loss of the Scorpion and K-129, but it doesn't explain all of them. For example, one of the most materially odd things about K-129 is that it had something like a dozen crew members on board who were not part of the normal compliment, and in some unrelated event the crew manifest was lost, so we don't know who they were. That certainly fits with a general pattern of Soviet behavior, suggesting that there were intelligence officers aboard (besides the routine intelligence officer included as part of standard compliment). But that doesn't mean there was some kind of rogue KGB plot or something as some believe; it's more likely that K-129 had some kind of special but relatively routine intelligence assignment. It could support the idea that the USSR searched in the wrong area to conceal a secret assignment for K-129, perhaps close-range observation of US naval exercises. That makes some good sense in the political context as, both before and after the loss of the K-129, the Soviet Union had been extremely critical of the US and UK for performing close-range submarine surveillance of Soviet exercises---they wouldn't be keen to admit they were doing the same.
But these are all just theories. The evidence doesn't provide an especially conclusive explanation for the loss of K-129 or Scorpion, and it is doubtful that we will ever really know what happened. But there are theories to explain both losses that are more likely than KGB schemes or dramatic events of secret military history. Both may have been lost to malfunctioning torpedoes that armed and detonated in the tube or were even fired and targeted their own ships---both known hazards at the time, and in fact something that the Scorpion had survived once before. There are possible mechanical failures that could have caused either sinking. Extensive investigation of the Scorpion incident lead to design changes in later submarines to address some possible factors in the loss.
This is all good to keep in mind in the case of the Titan. Undersea losses like this happen very dramatically and the evidence is difficult to recover and analyze. We may never have anything but speculation as to the exact failure chain.
One of the reasons these theories exist is because four submarines were lost in 1968. That's a substantial portion of the total noncombat submarine losses ever. It's obviously appealing to come up with some kind of unifying theory, but as far as anyone knows it was just a coincidence.
