The first lion seems in a bad shape, though. That being said, the video mentions that he strayed a bit from his family's territory. Which suggests that lions are not that safe alone.
In general, if you read about the savanna, the consensus seems to be lions and hyenas tend to avoid picking fair fights with the other, because both pose a serious danger. And lions very often steal hyena's kills, subverting the image from The Lion King.
Hyenas are very clever social animals and very good hunters. And very dangerous, too.
Hyenas are very clever social animals and very good hunters. And very dangerous, too.