If the Leo is getting a "beatdown", why draw a weapon? Could you not intervene without drawing a weapon?
Sure. Then about that time another LEO shows up and shoots you and the perp. I feel better already.
Lets say there is a white man attacking a white cop.
A black man steps in to help the cop.
Then another cop shows up.
Who's going to take the first bullet?
Unless I'm in a very remote area, I'll just mind my business and take care of me and mine, without getting shot, tazed, beat, sued, or incarcerated.