Any reasons for you to say this? Like examples or scenarios in a start up environment?
I don't have any examples, but the person could be committing fraud in some business practice which would be discovered if someone filled in for them one day
One common technique is for an accountant or bookkeeper who handles accounts receivable to prematurely write off overdue customer invoices as uncollectible bad debts. Then when the customer eventually pays the crook keeps the money.