It's true that it's not a good idea to interfere in nature but when it comes to a distressed female impala stuck up to her neck in mud at sundowners then exceptions have to be made - albeit poorly thought through exceptions!
Remember, when attempting to rescue any animal from a waterhole - always remove your phone from your pocket first! Oh, and probably not a good idea to attempt this sort of thing inside a National Park where authorities don't look too kindly on people getting out of their vehicles and man handling the wildlife.
By way of a disclaimer, this episode took place on a private concession!