Problem: Continue the following story.

Hunter did not play sports in high school but Ian did because 
Here's how I want to continue it: Hunter was too weak to participate.

Problem: Continue the following story.

In two incidents, Natalie managed to avoid hitting a pedestrian but Mary did not because 
Here's how I want to continue it: Mary was being careless.

Problem: Continue the following story.

Justin went to check on Christopher at their dorm, but no one was there. 
Here's how I want to continue it:
Justin was worried.