This report is so full of unsubstantiated speculation, it is next to worthless.  Best to wait and see.  Your skepticism regarding CIA submarines is well-founded.  A rogue CIA submarine is about as believable as a secret CIA mission to the Moon:  impossible to conceal. As for what might happen, it is more plausible to think that a US sub may have detected the Russian sub where it ought not to have been.  The Russian sub would have been embarrassed (not supposed to be detected) and would have withdrawn.  The US sub could have made its point by dogging the Russian sub and pinging it regularly with active sonar to make it obvious it was tracking and following them.  Submariners pride themselves on their stealth.  Having someone following you ringing a bell would be shameful to the Russian submariners.  And that would be good enough. Other things can happen, but a fire in a submarine is a major disaster.  At least one Soviet sub was lost because seawater penetration into a missile launch tube caused a propellant fire.  Loss of integrity in a compartment could have let high-pressure seawater into the compartment, causing drastic air compression, head injuries (sinuses, etc.), and possibly a fire resulting from the increased air temperature or reaction with seawater.  That's a big if, and it is only offered as an illustration of possible explanations.  So, be patient and set aside these panting speculations.