I think it is unfair personally. If it was clear you meant that answer, it's pretty lame, especially if you only slipped up once in not crossing.
Unless you did it for all of them, cause you should really read exam instructions I dunno, it's still petty but probably in the same league as losing a mark going 10 seconds over in speeches etc.
Yeah it was only one question! And I legit changed it in the last 5 seconds of the exam. And also some other girl made a mistake and ended up writing the correct letter.. which was also against the instruction ?
It does sound unfair but there has to be a line drawn, because then everyone can do their own thing. And I think it's because in the HSC you would have lost the mark as computers mark them and can only mark what's shaded not circled.
Hopefully you won't forget next time
Consider this though, markers should know that the trials are a stressful period. If its a minor lapse like "circling" the bubble then I think it should be let off...
Inform your Head Teacher for that particular subject or ask your teacher why he/she awarded the other person the mark, but not you. Show him/her the paper of the other person. Sometimes teachers are in a good mood, so decide to give the mark; however, somtimes teachers can be in a slightly different mood and not award the mark.
I think its unfair, especially considering that the other student was awarded the mark. But equally, its fair because you wouldn't get the mark in the HSC. That being said, I think the lesson is learnt so go chase up that extra mark!