In a chemical plant you can get spin back of the pump and motor possibly destroying one or both. In a pool this would not be a problem so much, but a check valve would be needed for an AG pool, unless there are inlet and outlet block valves to the pump that can isolate it. IMHO a check valve is more reliable, even if there is a slight drop in pressure.

There is no potential danger as such, just be aware when the pump basket lid is opened. This is not the problem with an In-ground pool.

Pat