There was a good reason you didn't fly missions without someone to have your back. And when a string of bullets ripped across the cowling and Greg's Corsair started sputtering out black smoke, he was painfully reminded exactly why that was the case.
There wasn't time to ask about Jim's assignment history when it had come up. The only thing on Greg's mind at the time was finding Dobson before someone got hurt. When Greg did find out, it didn't exactly make him feel any better about how rotten this whole day had been.