I think that view is historically validated in that, in wartime, one side would steal the other's encryption hardware (e.g. the Enigma machine) and be able to piece together a meaningful description of what it's doing, without access to the original designers, and even get to the point where they could pose what encryption function they're trying to reverse.
Of course, there's a key distinction there -- those were largely mechanical systems, while the question here is about tiny microprocessors. So I'd agree there's a sort of pre-requisite that physicists be aware of the existence of some key primitives that the system operates on (here, current, voltage, electricity, etc. along with the ability to see small enough parts). If that's what you meant by being "trained in computer science" then I'd agree, though that's a non-standard use of the term.[2]
In any case, there's more to the physicist's toolbox than closed-form analytical equations.
[1] My earlier comment: https://news.ycombinator.com/item?id=16818220
[2] Per the Dijstrka quote ("Computer science is no more about computers than astronomy is about telescopes"), compsci is about the limits of computational processes, not electronic hardware per se.
Off topic, as the origin and precision of the quote doesn't affect your point, but: AFAICT the closest Dijkstra actually said to this was in https://dl.acm.org/doi/10.5555/25596.25598 :
> As a result, primarily in the U.S., the topic became prematurely known as "computer science"---which actually is like referring to surgery as "knife science"---and it was firmly implanted in people's minds that computing science is about machines and their peripheral equipment.
There were two reasons for this tradition. First, physicists are often called upon to act as multi-disciplinary problem solvers. Second, experimental physics is almost exclusively electronic and computerized. Things like data acquisition boards for personal computers were only beginning to be commercialized, and a lot of us rolled our own gear.