Lets review here and see if we cant resolve this issue.
It has been noted that many times, Killa Kid has been trading IVs that are later found to be wrong. This could be caused by a number of factors, inaccurate IV checking (Serebii is notorious for this) being a likely culprit. Or it could just simply be a case of KK's inability to add up correctly. At the minute all there is circumstantial evidence in that regard. While trading inaccurate IVs is a blacklistable offence, especially when done with the knowledge that they are wrong, I'm curious as to why they are so bad and have been traded for so long. It is easy to make mistakes sometimes, but not such vast ones as these.
FearthePika, I know you want to stick up for Killa Kid, but consider the possibility he may be in the wrong, either by design or by accident. I cannot clone myself unless it is on Emerald, so I know how much of a pain it is getting others to clone for you. That does not change the fact that KK has been trading wrongly-labelled stuff, and several times, even when the mistakes have been pointed out to him he continued to trade them.
It is hard to say whether a blacklisting is correct in this instance. I'm inclined to err on the side of caution, and maybe when KK learns to count his IVs correctly we can consider moving him to the probationary list.
EDIT: alternatively, maybe you could get an established member to check your IVs for you, just to double check that people are getting what they should from you.