Spamsickle, the point isn't that a single short exposure will damage it but that there's a cumulative effect. I'm sure you've seen old faded, brittle paper before! Your curator is fidgety because they have to deal with an aggregate of people all of whom think to themselves, "Well, this one small bit of light/whatever won't hurt it any." But yes, it doesn't matter much if you're not shooting rare or valuable materials, as many people aren't - the reason I've been bringing these things up is because some people are, and it's important not only to consider protecting the documents, but to consider the requirements of the environments they'll be working in. Given that those items are the physical property of someone else, it's important to be able to adapt yourself to their rules.
Glass and acrylic do both block most UV light, but I'm not sure that the glass that comes in standard consumer-level halogen lights is enough to protect documents.
Edit: On UV filters, check page 20 of chapter 3 of the Red Book
. They mention that window glass does filter out UV below 330nm, but not above that. There is separate UV film that can filter out light above 330nm, but that's not going to be built into your standard consumer-level halogens. UV film is pretty easily available though, if not dirt
The opinions expressed in this post are my own and do not necessarily represent those of the Canadian Museum for Human Rights.