Y'know, there's a whole lot here we don't know. There's nothing here about what gender or race of the sailor whose shirt he grabbed. There's also nothing about other things the CMC may have done - and I've seen a lot of CMC's get away with a lot of things. What's more, it's not like this CMC got 'fired' in the civilian sense - he almost certainly lost not one penny of pay. He simply lost his position.
I remember a carrier CMC - he was next in line for fleet CMC - who got fired for what he did on liberty (in Hobart, Tasmania, IIRC). The chief master-at-arms saw the CMC getting a lap dance from a female master chief where less senior personnel were present, and rightly blew the whistle. Sure, we can say that what people do off duty is their business, but the CMC was effectively in the direct chain of command of the female master chief - he would have had a direct effect on her career. So this was certainly out of line.
But the CMC was a popular person in the Chief's Mess - and so, because the CMAA blew the whistle, he was immediately ostracized by almost the entirety of the rest of the chiefs on board. So in my retirement ceremony I made sure to point out what this chief - whom I hadn't liked since forever - had done the right thing, that he'd shown courage to blow the whistle even though he had to know how it would affect him and his career. The others at my retirement ceremony didn't like hearing this, but I didn't care - it was the right thing to do.
So...I'm not going to pass judgment one way or another on CMC Helwick - we simply don't know the backstory.