Here's something to think about.
Say you're employed by a company that makes confectionary (candy / lollies / sweets / etc.). They have a particular product that comes in two colours, red and blue. Your job is to make sure that every packet of candy coming out of the machine has the same number of red and blue candies inside it. The machinery pumping out the candies gets progressively faster over time, and it gets to the point where you start to doubt your ability to accurately count the number of red and blue candies as the packets wiz by on the conveyor belt. You decide to quit your job in fear of making a mistake.
A few months later you purchase a packet of candy and notice that there are significantly more red candies than blue candies in the packet.
The question is: can you (morally) have a clear conscience?