The craziest emergency procurement I have ever been involved in was renting an airplane to bring back a heat exchanger from Houston for a shutdown I was involved in at a refinery. It was exciting and terrifying at the same time because so much was riding on the delivery of the unit.
The exchanger was not able to be shipped the long distance from Houston on a truck because of the time it would take, the potential for damage and the logistics required for the transportation regulations.
This is a good example of a valid emergency procurement because of the need to satisfy a requirement that cannot be satisfied through normal procurement channels.
When involved in an emergency procurement the exercise of good judgment is definitely required. Regulations, unfortunately, can open the door to broad interpretation and, in many cases, abuse.
You should always evaluate each situation on its own merits and seek the means to provide full competition, if at all possible or at least the maximum competition practical given the particular circumstances. As it is often said, the failure to properly plan ahead should not provide the basis for an emergency purchase. Truly unforeseeable circumstances that absolutely demand an immediate response do.