Sentence 1: Warren hired Denis on a whim. 
 Sentence 3: Denis was insubordinate and lazy 
 Sentence 4:  In fact, Denis' behavior was so bad it reflected badly on Warren 
 Sentence 5:  His supervisor called him to fire him for bad judgment 
 Option 1: He regretted his decision very fast. 
 Option 2: He didn't regret his decision.