In addition there must be a failure in the service implementation, because it must not sent an ok message, if the goods movement isn't done.
Last week I discovered, that sap ecc backend accepts per default faulty goodsmovement, if goodsmovement is done in connection with production confirmation.
There seems to be a setting in customizing of sap backend, to perform a check for the goodsmovements which are done together with production confirmation. If this is set, you get a warning, if you create a production confirmation with faulty goodsmovement with T-code co11n. But you can ignore this warning and then the goodsmovement is stored as faulty in the backend for later rework (T-code COGI).
Although the check for goodsmovements, included in production confirmation, is enabled in my sap backend, the SAP Enterprise Service ECC_PRODUCTIONCONFCRTRC alway responds with OK to faulty GoodsMovements.