Alot of things happens during exam period. One has to be very careful these days at writing his/her exams.

What you must do is 'Stay back after you have finished your paper'

Iv heard similar issue from different people that i think this writeup will help someone.

Its a story of my friend, after writing his exams he rushed, passed his answer script, went back to hostel. Unknown to him, another student have been monitoring him all the while. And this guy is brilliant. The other guy must have marked him from their assessments.
The new trend is, they know your matt. no., so once u finish and submit, they write your number on thier own paper and then wait till the exam finishes, during time to pass d paper, they submit their own paper with your matt. number and then do as if there was an error or something they forgot to write and then they search for your paper and write their own matt number on it and submit back.
What im telling u have dealt with alot of people who dont know this. Especially schools where it is fail and fail out.

This was the case of my friend but God was on his side as this guy was caught by another student who have been studying with my friend before exams and has known his hand writing.
So as he saw the guy changing d matt no., he raised an alarm and the story was something else. Students nearly killed him but for the timely intervention of security men as the staffs couldn't stop them.
My friend came and was shocked. Thats how he could have gotten a carry over after sleepless nights.
The guy was later interrogated and he said he has been doing it in previous papers. Luckily it was their first semester yr 1 paper.
Management has given instructions to anybody that feel that his scores after exams is not what he wrote to come for remarking incase there are other guys in this same act yet unknown.
The guy has been dismissed already. Please my friend doesn't want his school name mentioned,thats why i didnt include it here. Forgive us for that.
Lets all guard our efforts cos there are lots of unforseen forces fighting us daily in all ramifications of life. Help tell your friends.
God help us all.