Honestly, something like that would make sense. Or some other thing that made this possible.
Contessa is bullshit, but the things she does need to still be physically possible. Severing the shard connection with a couple of bullets was already stretching it. Using bullets to undo the changes made by Bonesaw/Amy and restoring the default insect control while leaving Taylor's mind pretty unharmed seems beyond belief.
I thought that maybe Contessa disabled the human control power with the bullets, and then had Amy just fix things to normal, but wouldn't that have meant no bullet holes at all?
Also why no insect control at the beginning?
Or just wanting to figure out what the thing is, and if it's safe. I mean they are in emergency mode right now, but "alien things connecting to people's brains and giving superpowers for unknown reasons on a global scale" is the kind of thing that should sound a lot of alarms no matter the circumstances.
Can it be trusted? Can Taylor be trusted? Even if Taylor can be trusted, can the thing take control and/or influence Taylor? Can it spread to other humans near Taylor? Can it potentially sabotage a rayshift if it wants? What does it want? And so on.
Da Vinci basically distracted Taylor with the idea of Olga coming back soon, but hard to believe she is just going to ignore this little bombshell.
Ehh, I find it believable that Contessa could shoot out a Shard connection given that it's rooted in the Human end of things rather than the Shard. As in I doubt Contessa would be able to shoot a Shard to precisely knock out the link it has to the Host, rather then knock out the link the Host has to the Shard. Though it is doubtlessly stretched by the bullet-hitting brain matter part, but people have survived worse and the brain is still an adaptable neural network.
I'd imagine the insect control was more a case of the Shard reasserting it's connection to the Host due to one reason or another. I presume it likely had something to do with the stress Talyor dealt with early on that lined up to similar themes to her Trigger, the Zion Hub going down, and a version of the Earth (a World) getting somewhat wonky metaphysically along with a whole string of Earths. The hardest part might be how the Shard 'sees' Chaldea, if it does at all, given that at least Gotiea blocked the Collective Beast 1 Pillars from being able to see inside as a Safeguard. Though it is unknown if that would extend to a Shard, given they presumably stretch the Magecraft/Technolgy/Age of Will-tech, or a natural phenomenon (which includes things like say a Dragon's fire breath, the Shadow of FSN consuming people, etc) instead, or any other Observer.
So it would less be a plot hole and more the Shard finally getting the chance to find them again across how many other Taylors it lost a foothold in.
As for the 'large data volume' not sure whether or not I should be surprised they found it so fast, or that they identified it as an intelligent agent rather than say a Psychic force, given the existence of such channels being known to grant Humans supernatural abilities outside the Common Sense of Man. On one hand, there have been a hundred (at least) Parahumans being examined by nominal science in the past without discovering this, and on the other hand, the Network went down alongside a deadline to safeguards falling apart. It likely also helps that it is partly Magecraft being involved as well, and we still don't know if in most Cycles most Hosts have lost Magecraft entirely as a standard or not. But it could also be an indication that Admin is investing heavily again in Talyor's connection and making up for the lost time by blatantly syncing records, or adjusting the power to whatever limited extent it can now without the Zion Hub.