A convoy/task force stack sunk by fighter bombers. This might be a slight problem, since the task force could probably have taken a few more hits, but the convoy ended up defending. I suppose this could also apply to stacking hard to kill units with 'regular' units (or even doubling up hard to kill, since a single kill gets them both). This could just be a case of 'stacker beware' and not warrant any kind of change.
I got another convoy also, and I think a couple planes.
I got another convoy also, and I think a couple planes.