Yes, I did have this experience. Made a trip to Silicon Valley to talk over a licensing agreement with a tech giveback (by us). One of the ideas was shot down by a senior tech guy there as "unworkable". We (stupidly) dropped the idea after being ridiculed for it.

More than a year later, he and the head of their marketing took at exact idea, created a company around it, and later sold it for more than 230 million.

So, yes, it can happen.