Testing the "if" is science - but difficult without a framework helping understand "how". Testing only if, in a vacuum, isn't enough - and it is a tool on the path to understanding "how". This allows such things as using statistical models (if one has an idea of distribution, for example) to help refine the "if" tests, and narrow down exactly what your "if" experiment tested.
I don't think you can have science without both, and I think defining a body of theory is the more important aspect.
I get in discussions about philosophy of science all the time because I am passionate about it. But I am very disappointed because it turns out that other people who are passionate about science and the philosophy of science haven't really done the reading. This discussion is a prime example.
It makes me feel like nothing more than a conduit, copying arguments out of old books and pasting them on the internet.
The original sentence, "One could argue that..." is poorly worded and confusing. Maybe you could take this opportunity to clarify what you meant.
I'm not really interested in litigating who said what. I'd rather understand what you actually mean, rather than try and attack the wording that you happened to use.
To clarify what I'm saying: Testing "whether" can be science, without testing "how", and vice versa.