(1) If we construct a theory based upon multiple hypotheses, and if experiment condemns it, which of the premises must be changed? It is impossible to tell. Conversely, if the experiment succeeds, must we suppose that it has verified all these hypotheses at once?

It is interesting to note that something like (2) is commonly seen in the literature in generative grammar.

(2) In this work we have argued for (A). The argument is based on various theoretical assumptions that have been made in the literature, and if successful, it provides further evidence in favor of the assumptions. Thus, we have further evidence for (B), (C), and (D).

The author(s) of a passage like (2) might therefore respond to the second question in (1) as in (3).

(3) We do not say that it verifies all these assumptions/hypotheses at once. We only say that it provides evidence in favor of the assumptions/hypotheses.

Quite relevant to the discussion here is the "deceptively easy" part of footnote *3 in [8152], repeated in (4) below, without reintroducing the font formatting (see [8152]).

(4) *3 I now feel that I should have emphasized in this pace a view which can be found elsewhere in the book (for example in the fourth and the last paragraphs of section 19). I mean the view that observations, and even more so observation statements and statements of experimental results, are always interpretations of the facts observed; that they are interpretations in the light of theories. This is one of the main reasons why it is always deceptively easy to find verifications of a theory, and why we have to adopt a highly critical attitude towards our theories if we do not wish to argue in circles: the attitude of trying to refute them.

It perhaps requires some discussion before we assess the content of each of (1)-(4), but it seems to me that how one reacts to a passage like (2), and what position one takes in regard to the issues raised above would define, at least partially, what kind of research one wants to do and what type of researcher one wants to be.