You have to get the opposite of what you think or expect if something is ironic. I don't think replying with "he" instead of "it" is something opposite of your expectation. It is rather surprising as if it were spoken by a mentally insane or retarded person. It is not a humor, either.
Here are some examples of irony in Merrieam-Webster.
“What a beautiful view,” he said, his voice dripping with irony (atually, he is not looking at a beautiful scene), as he looked out the window at the alley.
She described her vacation with heavy irony (she is resting, not STUDYING) as “an educational experience.”
It was a tragic irony (he got sick by his own worries) that he made himself sick by worrying so much about his health.
Your case is just one of many misunderstandings that can happen in your life.