So Hal, the phone call started at some unknown time AFTER the event started.
The animals killing the child would not have taken five minutes. It would have been over quickly.
Well, it may or may not have taken 5 minutes. Sadly, the child was dead by 10 minutes when they reached him. However, it may have taken multiple minutes. If you care to search Youtube, you can see what African Painted Dogs do with their prey. In some cases, they will alternatively strike/bite and back off and this may continue even after the prey is down but still alive and last for minutes. The prey may be evicerated, but still alive and struggling at the time. As with many types of carnivore kill, the kill often is not what we would consider to be quick, clean, or humane.