Last night I saw Ewer's "spike" on YouTube.
Maybe I have seen something like that, but I wouldn't have characterized it as a spike. He slammed the ball down, which I suppose counts, but I think of a spike as the Gronk motion. That's how players used to do it....they wound up almost like a pitcher, and made a big arcing motion with their arm and their back leg comes up like a pitcher's too. It's forceful, very demonstrative, and I guess could be considered aggressive.
What Ewers did, that probably does happen in the SEC without flags. Not that I recall it, but that doesn't mean much. That wouldn't have stood out to me enough to remember it. If the ref got on to him for that, that's kinda ridiculous. That's way different than what I think of as a spike.
Not that I'm against the Gronk spike either.