I heard this story more than once and it got me thinking about a couple of things. The first thought revolves around how the IE voice exam is graded. For the IE voice it is a hybrid method of running automated scripts and proctor review. Since a portion of the grading is automated, you have to ensure you are very specific. If you overlook or miss any aspect of a question, no matter how small the miss, you will get zero points.
Another thought was about the relationship between requirements in the lab. While the lab is made up of individual questions, it is supposed to act as a seamless solution once you complete all tasks. This means that when you work on one question, you have to ensure it does not violate the requirements of another question.
Enough of my pondering, let's get to the point. While I believe it is remotely possible that an exam is unfairly or inaccurately graded, I believe it is more likely that small oversights will derail your efforts. The first "I shoulda' checked that" tip of the series: Checking Network Clocks.