I got myself in a similar situation (from what that screenshot describes) when I flew my meek zeke into an enemy dar circle at 10K-ish. The main fight was not too far away at another enemy base, but nevertheless, five or so enemy cons decided to up and go for the one and only dot in that particular base's radar. Just li'l ol' slowpoke me (and not much of a threat). I managed to shoot down three of them, an F4F, P38(j?), and a Yak9U before two more unknown cons shot me down.
Again, I got myself into that situation, but my main gripe at the time is that it appeared that the enemy cons were eager to shoot me down only to compete amongst themselves for the one and only kill in the vicinity. Typically if the situation were reversed, I usually ask before jumping in on an enemy with a teammate.
Oh, well. Those Rooks had to work at killing me anyway, so it wasn't all bad.