Any mismatch between the barcode and the candidate sticker can cause the marks being reflected against a different roll number. In other words, if on the OMR of candidate X, by mistake the barcode sticker of candidate Y was affixed on the front page, (s)he would get score of Y candidate than his/her own.
Hundreds of CLAT takers are speaking out on various Facebook forums and otherwise about what can be at best understood has a large scale blunder by GNLU in checking the OMR based CLAT answer sheets.
UPDATE: CLAT Results Withheld
Due to some technical discrepancies, the CLAT 2014 results declared on 31 May 2014 stands withheld