I took the Itani Test Pilot mission in Deneb K5, it sent me to Deneb O7.

In the O7 there was a serco defense turret, and it immediately started shooting at me. While I was running away from it, bots jumped in, agroed the turret, and the turret killed them all.

Now the mission is in the "completed" state, and I don't have access to X1. Imo, this should have failed the mission.

Please, reset this mission for my acc.

We reset the mission for your character, you may take it again.
Also note, in Itani space, you need level 9 Light Weapons License to gain access to the X1.