Right is right so any discrepancy will be magnified or minimised by how well the initial set up is done! Most people and jobs don't need that level of accuracy but the better you get the initial set up the bigger the mistake you can make before it becomes critical!
Lol that's always fun but they should of checked really! To be fair I was thinking more about some of our newer machines that refuse to do some or all of there actions when wired the wrong way!