A retcon following Infinite Frontier establishes that Savitar, escaping his imprisonment at Barry's hands in the Speed Force, was responsible for the deaths at Sanctuary in Heroes in Crisis, not Wally as originally believed.
A revision of the storyline following Infinite Frontier reveals that Savitar, having escaped from Barry's captivity in the Speed Force, was actually responsible for the fatalities at Sanctuary, contrary to the initial assumption that Wally was accountable.