George had breathing problems prior to officer kneeling on him.
Understandably, cops have heard all kinds of excuses from suspects, especially from people under the influence of alcohol/drugs, and are reluctant to go along with just anything people claim or say to them. George did not want to be in the cruiser because he said he was claustrophobic, even though he had no problem sitting in his car when they approached him.
These cops, however, complied and allowed George to exit the vehicle and lay on the ground as he wanted. The could have forced him into the back in and slammed both doors. It's seems from the video, they were waiting for him to relax and come down...which would have worked on sober person. Unfortunately, George was not sober. This was not a murder.
I do think better training, and medic in every cruiser would have made the difference. But this requires more funding, not less. Medical school is expensive.