 What can we infer from the passage that caused Mr. Higgins to go crazy?
CALL HIM NEMESIS By DONALD E. WESTLAKE Criminals, beware; the Scorpion is on your trail! [Transcriber's Note: This etext was produced from Worlds of If Science Fiction, September 1961. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] There was Mr. Featherhall at his desk, refusing to okay a personal check from a perfect stranger. There were Miss English and Miss Philicoff, the girls in the gilded teller cages. There was Mister Anderson, the guard, dozing by the door in his brown uniform. There was Mrs. Elizabeth Clayhorn, depositing her husband's pay check in their joint checking account, and with her was her ten-year-old son Edward (Eddie) Clayhorn, Junior. There was Charlie Casale, getting ten dollars dimes, six dollars nickels and four dollars pennies for his father in the grocery store down the street. There was Mrs. Dolly Daniels, withdrawing money from her savings account again. The man who had spoken withdrew a small but mean-looking thirty-two calibre pistol from his jacket pocket. One of the others took the pistol away from Mister Anderson, the guard, and said to him in a low voice, "Think about retirement, my friend." The third one, who carried a black satchel like a doctor's bag, walked quickly around behind the teller's counter and started filling it with money. The man who had first spoken herded the tellers, Mr. Featherhall and the customers all over against the back wall, while the second man stayed next to Mr. Anderson and the door. But he'd been moving too fast, and so had Miss English, and all he hit was the brass plate on Mr. Featherhall's desk. Meanwhile, Mr. Anderson went scooting out the front door and running down the street toward the police station in the next block, shouting, "Help! The man with the satchel came running around from behind the counter, and the man by the door tried to keep Miss English from scratching his eyes out.
 He had flunked an exam and was overwhelmed with stress.
 He was no longer happy with his wife hence why he murdered her.  He was tired of his job and didn't want to return.  He was overly tired and delirious.  He had flunked an exam and was overwhelmed with stress.