He abandoned his brother, who was in a life and death fight with the lion, so that he could call 911.
Didn't carry a Buck knife into the woods, but he had his cell phone.
Just had his stomach clawed pretty bad. Might have been in shock and thinking getting help was most important.
I'm doing Monday Morning Quarterbacking, but he could have popped the lion's eye out. I know you can do it to a human in about 2 seconds, using one finger, probably could do it to a lion.
A lot of folks don't know about not fighting traditionally (in other words "fair").
One could probably have looked around and found a thumb sized stick and shoved it up the cat's azz too.
I'm guessing, as others point out, after beating on the thing with his hands he decided it was time to get help.