Clearly JB has memorialized that Ivy [Harry's friend] had made arrangements with Mab [the evil Fae queen that Harry is DESPERATE to get away from] for Kincaid [the assassin Harry contracted to kill Mab's new Winter Knight] to shoot Harry through the heart [a more survivable injury than through the head] so he can fall into the lake where Mab [the evil Fae queen that Harry is DESPERATE to get away from] can save him and then [after 6 months of Harry being literally at death's door] she can take him to the center of her power where he is completely under her control while he recovers from the most compromised physical [and maybe mental] state he probably has ever been in. Guys, I think this part of the conversation has jumped it's shark.
If Ivy had said nothing, done nothing, Harry most likely would have died from a bullet in the head. Sure, surviving and winding up in Mab's clutches isn't the best place for Harry to be, but considering the alternative... Alive and in a bad situation is better than dead and gone. And what else could she really do? The Archive is supposed to be
neutral, aware but interfering as little as possible in events outside of the Oblivion War. So my WAG is, Ivy was extremely limited in what she could alter, and changing Kincaid's aim was the absolute limit of what she could do. What happened after wasn't something she could control; she had to have faith in Harry to get through it as well as he could. (I could be wrong, of course, which is why I'm labeling this theory a WAG. YMMV.)
The notion that Ivy tipped Mab off interesting, but I suspect Mab would have been able to find Harry without it, through the tie of Winter power that binds Knight and Queen. So... it's a possibility, but I'm thinking it's less than likely that Ivy had to contact Mab at all. Again, YMMV.