C.J.
If she has the class weekly or tomorrow, I wouldn't take it. I also wouldn't throw my husband under the bus.
I would talk to him and say, "I know you didn't know, but I told her she could, her teacher told her she could, so next time, feel free to call if you think she is trying to pull a "fast one" on you."
I would tell daughter when she cries about it. "Sweetie, don't worry about it. I didn't tell daddy and we just got confused. You can bring it next time."
It shows her that 1. mommies and daddies can make mistakes 2. models behavor of cutting people some slack 3. shows her that just because a moment passes, the experience isn't ruined (she can bring it another day).
beyond that is shows solidarity between you and the hubster.
Well, good luck with whatever you choose to do:)