Taking responsibility means that you commit to doing what’s necessary to make something happen – and that you pay for your mistakes.
We are often reluctant about the second part – I think with good intentions. But if people keep making the same mistakes at someone else’s expense, there’s a good chance that they don’t really understand the cost.
Having an expectation that people pay for their mistakes – for example, for any item with incomplete paperwork in an expense claim – is uncomfortable for whoever enforces the rule as well as whoever pays, and is a good way of reminding everyone that you’re taking things seriously.