I am inclined to disagree with everyone and yet I feel that I agree too. I guess I am in a contrary mood today.

Was it a success? Yes.

Was it a failure? Yes.

The outcome was satisfactory. No more, no less.

The process, as well as the execution of it, was a success as, due to the rollback, the process was successfully completed i.e. to a known process completion state.

The aspect overlooked was a failure but, as others have pointed out, may not be too bad if learnt from.

A foreseeable failure occurred but recovered to a operational state in a managed way. Outcome: satisfactory.