When doing your investigation remember that the person who replaced a chip may not be the person who put in the bad chip. Another participant down the line may have upgraded his chips. It is sad that this has happened several times. I know that it happened to me in several of the RR's that I ran in the past. On the other hand, if you ended up with some good chips that you needed for your collection then maybe the damage is minimized. that does not excuse the person who put in the bad chips though.