I was just asking about how similar the surfaces are between the grips are
The grips are going to feel basically the same. You might be able to tell them apart in a blind test if you had some time and your wits about you, but in the middle of a fight or struggle your brain is not going to notice the difference.
This cop just had a brain fart in the middle of a stressful event. From the video I saw he clearly ment to draw his taser, testimony says he announced “taser” and from the video I saw he looked shocked that he’d fired his weapon instead of his taser. It was a mistake but not one that rises to a charge of manslaughter or negligence.
Appropriate response would have been a payout to the family and better training for the officers. Then rioting!