I'll let one of the experts clarify, but at least while you're building one of these missions, you mustn't exceed the maximums or minimums of a particular plane's flight model.
The next best answer I can think of is to film the engagements and replay it with an eye on what the AI is doing. I found that a second plane I wasn't tracking would bounce me unexpectedly, so perhaps that might be what's happened to you. htc is still trying to prefect this so I'm sure your observations could be useful.
One of our complaints is the AI's current ability to fly under the ground instead of colliding with it. This is obvious when the mission is air starting and looks terrible. I can't say if it happens during a fight, they keep me far too busy to notice.