Macacan, here's how I see it, which may or may not be the "correct" way at looking at it:
Let's say we're playing a rebuy tourney. I go all in, and you call me, and bust my quads with a royal (yeah, i know i'm being brutal, but have lost this way once). Since you have more than me in chips, you've knocked me out. Now, I have the option of whether or not I want to rebuy into the tournament. I would think that either way, you would get the acknowledgment of my KO. Now lets say I do take that option, and later on, say at the final table, you bust me out again. You would then have technically KOed me from the tournament twice, although only the most recent would show up in standings.