There are obviously lots of things a CSD 'can' do on board. But this is clearly not policy or everyone would be doing it on every flight. And I know I see it very, very rarely. I am sure CSDs, for example, can routinely be 'allowed' to do it as a service recovery option if needed. But that doesn't sound like FlyingJ's situation. Rather than risk a good deed (the praise) turning bad (e.g. the CSD having to explain exactly what he did and why and maybe getting in trouble), I'd err on the side of caution and simply not mention it.