"How come many forklift operators seem to do many things wrong and never have an accident?"
I've lost count of how many times that was said or implied to me when I was training. A really good explanation for this is known as Heinrich's domino theory.
Heinrich was born in 1881 in Bennington, Vermont, USA. He served an apprenticeship as a machinist and was promoted to third assistant engineer before joining the Traveler's Insurance Company where he became the Assistant Superintendent of the Engineering and Inspection Division. He retired from there in 1956 and died in 1962.
He will be remembered because of his book "Industrial Accident Prevention: A Scientific Approach". The first edition was published in 1931 and he published three revisions in 1941, 1950 and 1959.
Many modern health and safety concepts are built on what Heinrich wrote about such as the incident pyramid and the loss control triangle. His definition of an accident is "An unplanned, unexpected, sequence of events".
Heinrich's domino theory can be used to answer the question posed at the top of this page. Check out the picture above. Let's assume that the pedestrian gets injured or killed and look at what could have caused it. Check out the next slide.