This happened to my gluten free pudding in CW on the way to YUL. The crew told me they had dropped it and there wasn't anything else gf that they could offer me (but they did bring me a banana from the club kitchen).

I think if things are dropped and there is no replacement option available then the crew will tell you just that I get irritated when my gf meals are not loaded (seems to happen a lot between LHR and BOS for some reason...) but the dropped pudding seemed to upset the crew more than me. I'm surprised it doesn't happen more often - it can't be easy to sort out those trays during turbulence!