That may happen more easily than you're suggesting. LLMs are masters at generating plausible sounding ideas with no regard to their factual underpinnings. So some of those computational bong hits might come up with dozens of plausible looking suggestions (maybe featuring made up literature references as well).

It would be left to human researchers to investigate them and find out if any work. If they succeed, the LLM will get all the credit for the idea, if they fail, it's them who will have wasted their time.