1: Most people do not perform well under pressure. While some do, it makes the majority of people nervous. When you are stressed your brain can forget things you normally would remember, and this can lead to sloppy mistakes. This means that, yes, they will be more likely to make mistakes.
2: Saeng is probably feeling nervous at first. She is being tested on something that she wants to excel at, and this can create stress. The tester wrote something down, causing her stress to increase, and we can see this causes her to make mistakes later when she goes through the stop sign.
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
