I was reporting to a manager on a very technical proposal. While I was describing my solution the manager interrupted saying a trick I used seemed implausible. Then I responded to him with a why. Expecting to hear his advice, I was irritated because he just said that he had never seen such a method before, yielding at him that if every method has been tried before what we are expected to do/create? He shut up.
Later the performance of my solution turned out very good and exceeded his expectation, but I realized that I can still optimize that project in where he pointed out with the trivial reason. I can find a reasonable drawback of my solution and a better version. But I think the truth is that every part of a solution can be optimized for any system, and his critic only let me pay more attention to that part.
Is it appropriate for a leader to prompt advice with no reason? I don't know what I could do had I were in his shoes. Any advice? Thanks in advance.