The show has long since established its "rules" for time travel, and thus far, one of the most pivotal ones has always been that the person going back in time would also exist in the past to which they're travelling. This vital rule is completely shattered here, without so much as an attempt of an explanation for the deviation (not to mention how this "cheat" pretty much nullifies the whole premise of the plot).
When Kamilla answers the baristas remark by saying "tell me about it" her lips do not move.
In all the iterations of Cicada taking various hostages, he always takes them to the same rooftop. Nora knows where he will be, and when, so she could just show up with the team ahead of when he arrives with his current hostage. It shouldn't take her 52 tries to think of this strategy.