@philipncohen That’s probably not a big deal, I admit! I would still be worried about creating a scenario where your silence/refusal to answer such a question for someone else could be interpreted as a bad thing.
On reflection it’s more accurate for me to say I wouldn’t share information about the discussion of their application, good or bad, but I’m not concerned with people knowing I’m on the committee reviewing their application (since my institution makes this information public anyway).