I doubt it was racism.
It was probably more the Christian in him talking:
'If this guy kills me, I go to Heaven. If I kill him, he likely goes to hell'
As opposed to understanding that as a Police Officer his job would be to serve and protect society. And as such, his job could include terminating a person that is a danger to society (and that would include terminating someone who is endangering your own life). A Police Officer, Christian, or not, cannot give a violent person a 'free-pass', as might a Christian surgeon. I'd still recommend the Christian surgeon not giving the raging bull a 'free-pass', but I could understand it if he chose otherwise.
Don’t make excuses for him. He said what he said because of the Ferguson atmosphere...pro black....anti police.