Your ideas are correct, your terminology is just off. If the documentation of Some_Method tells you to stuff the result into a scalar, it isn't returning a hash, it's returning a reference to a hash. You need to dereference (not cast) the hash reference into a hash, and then look up the key in a hash.

%hash = %{$hashref} takes the hashref and dereferences it into a hash, then $hash{key} will look up in that hash. You can also write $hashref->{key}, which dereferences and looks-up in one operation (and is thus much more memory-efficent for large hashes).