Uncritical Inference Test: Billy and Tom

The Story
Billy and Tom were lifelong friends. Everything they did was with the other in mind. They had even considered going into the ministry together, but had decided against it at the last minute.
Both were happy with the way things had worked out for them in the army. They had joined on the "buddy system" to insure that they could stay together, and that their friendship would continue. Currently, they were stationed at Camp Bingo, a minor supply base in a war zone, miles away from enemy action.
Things couldn't have been more perfect for the two of them.
One day while the two were on a routine patrol just outside the camp, an enemy soldier suddenly appeared in the bushes and opened fire. At least one of the bullets hit Billy.
Seeing Billy fall, Tom turned just in time to witness the sniper run off. Tom raised his rifle and took aim. He pulled the trigger, but there was no shot. His rifle had jammed. In an instant, he was in pursuit.
Moments later, he spotted the sniper who lay writhing in pain on the ground. The sniper had fallen after breaking a leg when he tripped on a prominent tree root overgrown with weeds. As Tom approached, the sniper began to yell, "I surrender! I surrender!"
Tom glanced over his shoulder in Billy's direction, then approached the sniper.
The Statements
____ 1. Billy and Tom had been friends all of their lives.
____ 2. Both had doubts about their religious beliefs.
____ 3. The sniper spoke English well.
____ 4. Tom and Billy graduated high school together.
____ 5. When the sniper opened fire, Billy and Tom were side by side.
____ 6. Tom walked with a limp.
____ 7. In his anger over Billy's death, Tom wanted to kill the sniper with his bare hands.
____ 8. Tom and Billy were unhappy in the Army.
____ 9. Had the sniper not lost his rifle when he tripped, he would not have wanted to surrender.
____ 10. Tom cleaned his rifle regularly.
____ 11. Camp Bingo was not in the United States.
____ 12. Camp Bingo was a dangerous place.
____ 13. The sniper was working alone.
____ 14. Another member of Billy and Tom's patrol stopped the sniper by shooting him as he was running off.
____ 15. Tom approached the sniper as he lay writhing in pain on the ground.