I understand what you're saying and agree that if they think they're telling you the right thing, there's no need to confirm the information, but at least two of us on this thread shared experiences where we questioned the information and still the CM insisted otherwise. That's when I think the CM should take a moment to confirm what they're saying.
In my case at BLT, the CM actually told me at least twice to take the monorail (at 8:15, when it wasn't running) before he finally gave up and got a times guide to check what I was telling him. Then when he DID see that he was wrong, he told me the only way to get there was to take a cab, which I thought then and know now wasn't true.
Basically, I think of it like the grocery store. I don't expect the cashier to double check every single price tag, but if I notice the toothpaste rang up the wrong price, I hope they'll at least call someone else to go check the sign, rather than insisting to me that I'm wrong about the sale.
We're Disney veterans, and it always makes me sad when things like this go on because I feel pretty informed, and if I'M confused, I can't imagine how stressful it would be for a family who doesn't know the right questions to ask.