I don't.
I think that the potential exists and they must investigate that aspect, and include it in all future investigations.
It doesn't mean that is what occurred in the McCain incident, but it means they know it IS possible.
It is one thing to hack into computers, we do it, they do it.
To plant something in software to cause an accident (even if one thinks there can be monitoring and full knowledge of ship movements, etc to make the casualty occur in the correct proximity of another vessel and cause an accident) is a fantasy, especially in light of it causing actual fatalities.
And furthermore, to think a potential adversary would do this to actually cause an accident in a busy sea lane with the express purpose of causing an accident, rather than doing it on the open ocean just to see if it works (in order to avoid a full-blown investigation which would uncover a vulnerability, sure to happen in the event of fatalities) doesn't make sense in any way. If a muslim group did it, they would claim credit. If the Chinese, North Koreans, or Russians did it, why would they do it to cause a collision, create a full investigation and forensic evaluation of equipment and logs, and lose a potential vulnerability to exploit in the event of a real shooting war.
It doesn't add up.
In addition, look at the statement by the US Navy: "...“We will look for a couple of things. One, try to confirm cyber did not have anything to do with the collision and then how do we move forward in making sure these are a normal part of these investigations,” she said. “It is something that we think about a lot and we have to have both the authorities and the human capital ready to respond...”
That is total, complete, and absolute ass-covering to show the entire world watching, that they are investigating this fully, and will work this into their standard investigative processes going forward.
I do root cause analysis, and have to present to people on failures. And what they want to hear is: what happened, why did it happen in this case, and what is your process going to be for preventing this from happening in the future?
That's is all this is. But the conspiracy theorists out there are grabbing onto this tidbit of news as if it were a life preserver being thrown to a drowning person, which is what they are.
The US Navy didn't need to issue a public proclamation to ensure they included this in their future evaluations. This is just, as I said, kabuki theater.