This sort of confusion about 'competent authority' has come because of the ignorance of Public Authorities about how to furnish info under
RTI Act. In the normal course most letters from Govt say - ' I am directed to say..' or '...hereby conveyed' or 'the competent authority has decided that....' so on and so forth. The person signing that many times does not know who that 'authority' is. It may sound incredible. But ours is an incredible India, in deed! When a PA furnishes info under
RTI Act it should not use such language and get bogged down with issues such as you have rightly raised.