So does it matter? Is this just a badly designed test and "real" 11+ tests would not have this problem? Do tests mostly have only one answer or do they allow all possible answers?
Assuming the test is multiple choice, are there are duplicate answers possible from the answer sheet? There may be many possible endings/beginnings to the pair of words, but if there is only one possibility from the options given on the answer sheet, then that is the correct answer.
Otherwise, in order:
a) No, it doesn't matter.
b) Yes, there are errors in some published papers and no, the real tests wouldn't have these problems.
c) Yes, there's only one correct answer in the real tests.