The problem about keeping secrets is that it can cause problems down the line. One such secret in Season 2 of The Flash was the arrival of Earth-2s Harrison Wells. The Earth-1 Wells, of course, was responsible for killing Barry Allens mother and is now as dead as dead can be (well, as far as comic book deaths go). So, anybody not in the know about the Multiverse concept will see the Earth-2 Wells, presume it is the Earth-1 Wells, and wonder just what the hell is going on. Still with me? Good. As such, Patty Spivot, completely unaware of an Earth-2 or the Multiverse, sees Harry Wells, presumes that he is Earth-1s Wells, wonders what the hells going on, then proceeds to shoot him! Okay, a little heavy-handed, sure, but most definitely a huge shocker. Luckily for Harry, the combined efforts of Caitlin Snow and Jay Garrick would eventually save his life, but for a minute there it was a little touch-and-go for Earth-2s Wells.