Well, I was able to pass the mission now, but things still aren't perfect. I took out Arjuna when the got in close, though I still got the debriefing message indicating that I shouldn't let them get beyond the 3k range. Anyway, after destroying Arjuna the Admiral told me to jump out and the AWACS jumped, but I decided to stick around. I got a scan of the Byrn corvette but the fighters all converged on me and then the warships started shooting at me. I led the fighters away from the warships, shot them all down, went after most of the freighters and took them down. Then picked a careful course towards the Ravana (I hadn't scanned it yet) and set about taking out the turrets from close in until I could get the scans done. That completed all of the objectives for me. I was hoping to snipe out the turrets on the cruisers and take a couple of them out before jumping away, but I was taking too much damage when a nearby Lilith targetted me with its AAA turret so I decided to make a break for it and jump out once I was out of range.
Aside from the debriefing thing, I would suggest giving the player a bit more time to scan everything before things take a turn, then make sure that if the player managed to take out any of the fighter wings, more are launched to replace them. I tried it over and over and never managed to scan EVERYTHING unless I did so AFTER the whole Arjuna situation, which I shouldn't be able to.
Regardless, thanks for looking into my initial problem and creating a resolution so quickly.