Here's the longer version for you: https://twitter.com/PDXzane/status/1284733976582615040
Not really sure what else to say, even if he had done something to provoke a response aside from shouting(you can read the multiple articles for details) he wasn't resisting arrest, was stationary and the federal agent broke his hand in two places[1].
I can't think of any situation where beating the shit out of someone who's standing still and not reacting is an appropriate response. Much less from someone who is expected to uphold the law and supposedly trained to deal with stressful situations.
[1] https://twitter.com/Tazerface16/status/1284849286237151232