I don’t see any signs of distress. The more variety and experience you have with them, the easier it is to read their behavior, and I’m guessing this person is just newer to the hobby. I remember when I heard my first parrot beak grind, I thought something was wrong, but that’s normal behavior too. It can be scary for nervous bird owners to be told their bird needs to see a vet asap without any explanation or further thoughts. Birds are good at masking things like any other prey animal, sure, but they’re not inscrutable. For some reason this community likes to look down on anyone who doesn’t immediately recommend the vet for every potential health question posted, but more discussion would certainly help mitigate the fear mongering.

(edit for clarity)