MAP test is so called the "computer adaptive test" or CAT. So if the kid guessed the answer, most likely, the computer would switch to the lower level problems. A few wrong guesses later, her score would be much lower than her actual knowledge level. Then she might feel more comfortable with the easy question and may start building her score back up.
Only in the extreme cases that the kid was in a totally "no-compliant" mood, the score would show quite a deduction.
In case that the kid was indeed in a "good" mood and she was smart enough to figure out the trick to get the best score was sitting at the computer for as long as the teacher allowed and think through the problems, then the score would show.
Lucky guess woudn't matter since it would introduce problems from more difficult level and the probabilities of more lucky guess would diminish quickly.
