There was a case when an Engagement Manager was on vacation, his project manager sent out an urgent PO request.
The related quotation and cost documents had already been approved. However, I learned that the final version of the contract had not yet been counter-signed. The internal policy requires that all contracts be fully executed with a signature from both parties prior to committing the company to any related third-party costs such as the issuance of a PO.
Although all the line items were keyed into the ordering system, the back-up Engagement Manager was able to use the information I provided to hold back approval of the PO. He was then able to raise the concern of unsigned contract and helped to communicate with the project manager.