[DennisP]

Sure but I don't think it's necessary to confirm where the AI got something. There might be lots of sources. I often tell someone some fact I know, mention a source if I remember it, and possibly google a link. An AI could do much the same. In training, the trainer could just check whether the claimed sources actually say something similar to what the trainee claimed it said.

In operation, the "trainer" could do the same thing in the background. And then of course, human users could also check up on the sources if they need to be sure of catching hallucinations.