A Victim Of Her Emotions
As I alluded earlier, even her boyfriend’s two deaths weren’t enough to bring down Caitlin Snow. In fact, they seemed to have lightened her up since we first met her character. But, when she finally gets over it, and when she finally falls in love again with Jay Garrick (the Flash on Earth-2), Zoom shows up and kills the guy, because that’s what Zoom does.
I’m sure there’s more to Jay’s death, but it hasn’t been revealed yet. And besides, with all these dopplegangers, anything can happen. Even still, this could be the blow that tips Caitlin over the edge, resurfacing all her grief for Ronnie and adding to it, creating a big icy snowball of cold-hearted rage. It seems pretty likely for a show in which characters so easily fall victim to their emotions.