HO's are a part of the game and you have simply got to learn to deal with them. Never fly straight and level with an enemy approaching from dead ahead. Weave from side to side, barrel roll, dive under, do ANYTHING to make it harder for him to get a good sight picture.
However, I DO sympathize. There is nothing more frustrating than to be flying along with a good deal of smash and have a newbie flying some heavily armed perk plane approach from your high 12 o'clock position, dive on you, open fire from 2.0k and get in a lucky shot on a vital part and destroy your ability to maneuver. Frustrating as all get out, especially if you know he's not any good.
Regards, Shuckins