Glad it has been all sorted now. TBH I would probably also provide the milk just so I'd know he's getting the right one. No you shouldn't have to, but for completeness' sake that's what I'd do.
Interesting the point about how CCCs have to provide an alternative at mealtimes. I am having a struggle with this but the other way round - I don't want them to offer an alternative to Nat! She has MEGA eating problems and I have only just discovered that if she doesn't eat her lunch (and she never does!) she is given a sandwich. I was actually really surprised by this and have asked them to stop it. I can't sort out her eating problems at home if she's getting this capitulation at kindy. It's a toughie, but it surprises me that it's something they 'have' to do.