If you work with public money - as I do - by providing a service, completing training, claiming travelling expenses, having a responbsibility for resources used in the process: - I am accountable for my actions. If I come into possession of knowledge that a colleague or any other person / organisation is potentially commiting fraud or any other potential criminal offence, it is my duty to report it.
What happens after that is up to seniors, but if there is a record - a paper trail - which shows that duty has been fulfilled, it doesnt matter if you are a sprat or a shark in a big pond.
Drink - driving - is an irrelevant red herring.