A brother officer in need...I am all in with both feet. That is the rule. Even if you know the guy and you don't like him and vice versa...you are in, all the way in. <------- That's the cop in me talking, even though I am retired now.
As a newly minted civilian...I am still rendering whatever aid I can. If he is in trouble, yet still up and mobile or in a cover position I will go to his aid yelling..."SHERIFFS DEPARTMENT" as loudly as I can. Then do whatever the situation requires.
If he is down...I am doing whatever it takes to help him get home to his family...I will obviously figure that out based upon the scene and immediate threats and his/her need of aid. I will summon EMS forthwith, and get backup rolling via his hand held or mobile unit in the cruiser.
If, like in the notorious video of the female officer getting savagely beaten on the side of the road, I am simply going to drop the subject in his tracks. No hands on, no warning or order to desist. Draw, extend, touch, press. Subject down, and right now.
Then again....if ANY woman is on her back on the side of the road getting beaten like that...well...you know us Arizona Men don't take kindly to some bad actor mistreating women or kids. I might just take the same action as above.