He was scared.

He realized his peril.

It was not possible for Helen to watch him killed, yet she could not bring herself to beg Bo not to shoot.

Helen confessed she was a tenderfoot.
"Get down, Bo, an' let's see how good a shot you are, said Dale.

Bo slowly withdrew her fascinated gaze from the lion and looked with a rueful smile at Dale.
"I've changed my mind.