Sullivan, a disabled veteran, was subjected to a "double arm bar takedown" face down from his truck to the pavement, breaking his back in multiple places. He was paralyzed and ultimately died from his injuries five months after the incident. Check out this short video Grits prepared about the episode.
The Austin Chronicle reported that "Sullivan's death highlights how an officer's cavalier use of force can turn fatal when used on a person with health problems." The Statesman had earlier published an excerpt of the dashcam video.
Here's a story from the Killeen Daily Herald about the episode and a lawsuit Sullivan filed against RRPD before his death. The Killeen paper also reported on his death. In his obituary, it was mentioned that his military service had been cut short by a back injury.
Check out a RRPD police report which indicated that officers were trained in this vehicle extraction technique, referred to in the report as "Points of Domination" training. Points of Domination is a term developed in a military context in Iraq and Afghanistan for clearing buildings in urban warfare settings. The report also indicates that Sullivan told the arresting officer his back was injured before they pulled him from the vehicle.
Here's the autopsy and another report from the Texas Rangers.
This episode was a needless tragedy. Sullivan's death points to how quickly law enforcement tends to resort to violent tactics in situations where deescalation is possible.