Unfortunately I've had way too many agents on various airlines make up stories of why I can't do something to avoid doing work. Usually involves vague appeal to security/local regulation. Like the QF agent in SYD who told me no way can I check bags through HKG on an overnight transfer, that would violate HKG security rules (CX has done this for me many times though).

I've had typically outstanding experience with CX check-in staff, so it would surprise me that they would try to avoid doing something that would be allowed. But it wouldn't be the first time I've ever heard a bogus story from airline staff.