The complaint does not allege that the Logitech wireless controller, the carbon fiber construction, Titan's innovative porthole, or the use of disparate materials with differing expansion/compression coefficients—four main areas of criticism—were individually responsible for the sub's implosion. But it does suggest that these systems could have together contributed to a "daisy chain of failures of multiple improperly designed or constructed parts or systems."
Titan was an implosion, so the pressure hull failed at some point, we just don't know what. While the Logitech controller is indicative of the decision making process, it's one component we can comprehensively rule out as causing the failure.
we cant rule that out yet! maybe someone played CoD on the way down, but the high latency made them ragequit, causing a high-quality, robust controller to be accelerated fiercly, piercing the crappy hull.
It's using the fact that it was a wireless controller used over Bluetooth as part of the evidence that they created a bunch of unnecessary points of failure.