I think a lot of time in the MA it comes down to how well you can manage yours and judge others E in certain situations.
For example, Xbrit just stated that you dove down, missed, and tried to flip back over and try to kill him again, but upon flipping, tried to kill your E while he was going slower than you, this caused him to get inside of you on the loop, and you lost all E causing him to be able to make a shot. instead you should have gone up and used your E to maybe rope him or fly away, regain alt and BnZ again. Just what I read, don't know if accurate.
This type of situation doesn't happen on a regular bases in the DA.
I think from what I understand, is that you are having trouble keeping E and/or judging another pilots E that is attacking you or who you are attacking. (does that make since?) This part takes a lot of experience and years to kinda figure out how fast a plane is going, and what it can do at that speed. So if you get in a 1 v 1 fight with a guy who dove down on you, you gotta keep turning nose down split S until he finally kills E enough to follow you in the turn for the shot, once he follows you, you can pull a quick lag roll maneuver and gain his 6 potentially.
If a guy you are fighting is obviously going slower than you (by you diving on him) make sure you regain alt upon the shoot and pass. You can even pull strait up and back just as long as you know you have more speed and climb than he/she. Don't just cut throttle immediately, flip over instantly, and expect to roll inside of him.
once you get in a legit turn fight then going slow becomes a grand factor. but other than that, until you really get a handle on E states and stall rates of planes and so forth, never assume the guy you are fighting is going to be an easy kill, always fight them like they are the best stick in AH.
Also Nerves come into play in the MA
Like Xbrit said, aiming is huge on being able to get the kill. Generally, not being able to make a shot, causes you to get picked, or have to flip back over and lose E trying to kill them again.
edit: Grammar