I think it's perfectly fine for the author to use AI in their research process, and it sounds like they weren't relying on it exclusively.

So they've already asked AI its opinion on the topic. They're explicitly reaching out to an expert because they've exhausted their ability to move forward on their own (even with AI).

If the expert just asking the same question to the AI and returning the answer directly - that's what OP has just done, and it actually is a waste of time. They're looking for insight, not just another quick response from an LLM.

I would imagine that letting the expert know ahead of time so they can research an answer (perhaps with the assistance of AI) would be a good pattern. But it has to be guided by the expert's knowledge - that's the whole point. Using AI is fine, and probably even good if it's being guided by a wise hand, but it isn't sufficient on its own, and bouncing answers directly back from an AI with no refinement is not useful, and dare I say it is somewhat insulting.