While working for the Seventy-Seventh District, McQuillen filed more than 60 use-of-force incident reports in four years, two of which involved chokeholds that resulted in the deaths of the subjects. When a task force was convened to address the use of the chokehold, McQuillen's history became public knowledge, and he was villified by the Los Angeles Times before being fired from the Department.
After leaving the LAPD, McQuillen bought a large share of Black & White Taxi Cabs. He worked as a dispatcher as well as part-owner. One of their most lucrative service areas was Hollywood where B&W held an exclusive franchise. In 2011 a competing cab company decided to challenge B&W for that franchise. The competitor hired George Irving to represent them before the city. Soon, three B&W drivers were arrested for DUI, and others were cited for moving violations. McQuillen became convinced that Irving and his father were unfairly targeting his business.
It all came to a head on the evening of 3 October 2011. A B&W driver saw Irving entering the Chateau Marmont Hotel. The driver notified McQuillen who went to the Hotel and gained access to Irving's room via the fire escape. McQuillen applied a chokehold to Irving to subdue him. When Irving awoke, the two men talked. When it became apparent that Irving intended to commit suicide, McQuillen choked him again and left. To give himself a solid alibi, McQuillen went to the bar at the Standard Hotel where a security camera documented his presence until 6 am.
Harry Bosch and David Chu took McQuillen in for questioning, but McQuillen knew in advance what they would ask and how he would respond. He told them enough to make it clear that he could not have killed Irving, and they released him.