Dogs are the bane of this route. The shot right after the first hostage will sometimes not kill the one after the sniper. When that happens it patrols to the far left of the level before you can be in position to get it with sniper support (wastes 5 seconds dropping down to get it at the end). The dog on the far right usually doesn't die when you shoot over the two hostages. Depending on how quickly it reacts, it can push you away from the hostages, which can waste just enough time to miss the elevator cycle.

Dogs aside, the final area after the elevator was butter smooth, saving the ~0.4 seconds needed to get an in game time of 1:09 (compared to other successes in the low 1:10).