I agree with Bleecker and doubt it's rabies. I used to raise rabbits, and wry neck/ear problems do happen. I'd catch it and take it to a vet, if only to get it euthanized.

You might check too with a vet. In Denver the vet clinics are required to take in wildlife at no cost to you. I took in a couple of rabbits one year, one with a broken leg - can't say the clinic was real thrilled and warned me they would euthanize vs treatment due to the cost, but better than seeing the animal suffer.