HR IS SAVITAR THEORY
Throughout the season HR has done some suspicious stuff, he has trained Wally to become the Kid-Flash, he knows a lot about the speed force, but in episode 318, HR was absent for most of the episode, he claimed he was on a date, but for TWO DAYS! but it is not what he was doing which was suspicious it was what he did next, be joked around, which made Caitlin laugh and fall into a seizure, killing her, and she manifested into Killer Frost.
I feel like none of these things are a coincidence, he trained Wally so eventually Wally would be fast enough to open up a portal for Savitar to get out, or for HR himself to get out. What if HR is Savitar. He could be, he has displayed some knowledge of the speed force, but triggering the coming of Killer Forst may just be an extra problem for team Flash to worry about while he plans his master plan.
But he was in the future vision, what if that was a hologram holding the gun, or a time remnant, who is inside of team Flash learning all their secrets. And who else thinks it is suspicious that the only two people that call Wally "Wallace" are HR and Savitar.
This is a crazy outlandish theory which may or may not is true Comment below your thoughts on the theory down below. As always thanks for reading, take care.