This was something that almost all the contestants enjoyed doing in over many different situations during the show. Disagreements and resentments with other contestants were often discussed in great lengths when the person was not there, in hushed little meetings as well as loud ones. Sometimes, softly spoken meetings happened when the person being talked about was right in front of them, just a few feet away.
And this wasn't well received. All the contestants who did this were reprobated by the public as well the host Kamal Haasan. It didn't matter whether it was done with good intentions or bad.
Lesson: Try to be as straightforward as possible, and discuss problems with people to their face directly.