I only just noticed this...
I can't speak for lactose intolerance, but, personally, I never trust chefs when it comes to advising me on the contents of their food. I've been caught out a few times by chefs who assured me that their meals do not contain wheatflour (the main problem for a gluten intolerant), when my belly told me, within minutes, that they bloody well do!
Of course, I wouldn't expect a chef to know everything about gluten intolerance, or, indeed, to give much of a damn. After all, sealing a piece of meat in a bit of flour - well, that doesn't count, surely? Except it does. For at least the next 24 hours.
So I'd advise you to watch out for yourself. Only you are responsible for what you put in your mouth, and an overworked, exhausted, irritable chef is the last person you should trust to give you informed advice and help, for all their good intentions.
By the way, can any other gluten intolerant people out there explain why I can have problems with the tiniest amount of flour (an oxo cube once ruined my weekend), yet seem to be able to drink lager beer (not dark beers, alas) with impunity? Is this common? Is it something to do with the processing of the barley?
Not that I'm complaining, of course. Perhaps I should question less and drink more? Bibere aude!
EDIT: Fredy at the Sonnenhof in Uetikon is a big exception to the rule - not only is he very aware of food intolerance (he also runs a school catering business), but has even come out of the kitchen to tell me that I can't have something I unwittingly ordered from the menu, because he knows it will ruin my evening. Top chap, he is. And his food is delicious!