Being in control of the tenor of a battle doesnt mean you control every event in the battle. This is an evil with tremendous resources. It is deeply entrenched. They still have some ability to affect events.

Once the Allies broke out of hedgerow country in France, it became plainly obvious that the wars conclusion was inevitable. But the Germans still were able to enact a huge offensive in the Ardennes that threw the allies back on their heals.

Similarly after Midway and the destruction of the Japanese carriers, the Pacific Wars ultimate victor was no longer in doubt. But the war continued for 3 more years.