Yes Lusche is correct, but I felt a need to further explain how kills are awarded.
The term "the most damage" is a little bit misleading. Simply put, the person who put the most lead into a plane up until a major part is destroyed that will doom the plane (such as a wing, fire, etc) will be awarded the kill. This has absolutely nothing to do with what actually becomes damaged on the plane.
Let me introduce a little scenario. Colmbo, lets see you and I are both attacking Lusche. Now, assuming that we are using the same exact ammo, lets say that I dive down on him while he's too busy drawing up a pie chart to notice. I get on his six o'clock and put nine rounds into his left wing. I don't do any real damage to his plane as far as destroying anything, but still my nine rounds did manage to hit him.
While I'm flying around working on another pass, you dive in and hit his left wing with only two rounds. After your second round hits, his left wing breaks off and he spirals down to the ground.
In this scenario, I would get the kill and you would only get an assist. The fact that you are the one who technically 'shot off his wing' has nothing to do with determining who gets the kill, as I put more lead into him.
Let's expand the scenario further and let's say that HiTech himself just happens to be online when this happens and he dives in on Lusche while he is missing a wing and spiraling down, hitting him with 25 rounds and blowing up his plane. In this case, HiTech would not even be awarded with an assist, as Lusche's plane stopped 'scoring' damage once its wing was blown off.
There have been times that I have seen an enemy plane fly by and I'll fly to it and blow it up, only to get awarded an assist. Yes it's aggravating, but obviously someone had already 'shot him up' before I got to him, even though there was no noticeable damage to his plane.