I don't think knowing what an array is would be something you can trivially Google. Sure you can look up the set of words that make up the definition, but that's not knowing what it is.

Something trivially google-able is like not knowing the syntax for generating permutations of a sequence in Python. But not knowing the idea of permutations would not be trivially google-able.

It comes down to what one considers "fundamental knowledge" that one needs to do the job. If you claim to be a programmer, but don't know what an array is, you're probably not actually a programmer. But not knowing esoteric data structure that one may encounter once in their career is not really indicative of anything.

Would you agree that what an instruction is depends on context?

Yes, ofc, he is applying for the "senior systems software development" role so there is our context.