My companion on the rock was very relieved to see me. My long absence, and the growling he had heard, had convinced him that the tigress had secured another kill, and his difficulty, as he quite frankly admitted, was how he was going to get back to the village alone.

I thought when we were climbing down the watercourse that I knew of no more dangerous proceeding than walking in front of a nervous man carrying a loaded gun, but I changed my opinion when on walking behind him he slipped and fell, and I saw where the muzzle of his gun--a converted .450 without a safety catch-was pointing. Since that day--except when accompanied by Ibbotson--I have made it a hard and-fast rule to go alone when hunting man-eater, for if one's companion is unarmed it is difficult to protect him; and if he is armed, it is even more difficult to protect oneself.

Arrived at the crest of the hill, where the man had hidden his boots, I sat down to have a smoke and think out my plans for the morrow.

The tigress would finish what was left of the kill during the night, and would to a certainty lie up among the rocks next day.

On the ground she was on. There was very little hope of my being able to stalk her, and if I disturbed her without getting a shot, she would probably leave the locality and I should lose touch with her. A beat therefore was the only thing to do, provided I could raise sufficient men.

I was sitting on the south edge of a great amphitheatre of hills, without a habitation of any kind in sight. A stream entering from the west had fretted its way down, cutting a deep valley right across the amphitheatre. To the east the stream had struck solid rock, and turning north had left the amphitheatre by a narrow gorge.

What made the narrator change their mind about walking in front of a nervous man with a gun?

 The realization of the potential for accidental discharge.

The correct option is: Option 2: The realization of the potential for accidental discharge.

In the passage, the narrator initially thinks that walking in front of a nervous man carrying a loaded gun is the most dangerous situation. However, their opinion changes when they witness their companion slipping and falling while walking behind them. In that moment, the narrator sees where the muzzle of the companion's gun, which lacks a safety catch, is pointing. Here's the relevant excerpt:

"I changed my opinion when on walking behind him he slipped and fell, and I saw where the muzzle of his gun--a converted .450 without a safety catch-was pointing."

In this sentence, the narrator mentions that they changed their opinion when they saw where the muzzle of the companion's gun was pointing. While the passage doesn't explicitly state "accidental discharge," it does imply a potential danger inherent in the situation. The mention of the gun lacking a safety catch adds to the sense of concern about the direction of the muzzle, suggesting a risk of accidental firing.

So, while the passage may not directly use the phrase "accidental discharge," the description of the situation and the mention of the gun's condition imply the potential for such an event, prompting the narrator to reconsider the danger they face.

Note: The original question asked in the paper was dropped by NTA. Therefore, a new question has been inserted instead of the original one.