This one is actually funny to think of. Not "wrong" but "entertaining".
So she set a lot of countermeasures so the people of her past didn't caught her, and was so sure about her Mondus Operandi...that, while dealing with said people, she didn't think her husband would catch on to her? Or rather, that he would be a "lesser evil"?
Going with this line, it's either that she was too arrogant to admit Sousuke would find out, or she knew Sousuke well enough to know he would not find out, and became surprised he did.
If we go through the second, it means Sousuke's call to action( Teraushi) probably acknowledged this, and gave him the necessary push.
Now, both my last 2 lines are theories, but my conjecture is that, maybe, the people after her are so much of a big fish( it could be well past Misato, at this point, but we don't know), that she thought Sousuke wouldn't find out, and he was lead into the whole Momonga channel thing to create a distraction for her to lower her guard, so they could create an opening. But that is by assuming her dealings pissed some big people, or more vengeful ones.
Regarding the theory about threats to Rika from influential and very dangerous people:
I don’t know the specifics of Japan, but if we’re talking about extremely wealthy and influential individuals, then it’s obvious: if Rika didn’t have kompromat on them with delayed publication or some other leverage, her days would be numbered. Yes, she hides her own and her children’s faces in social media photos and changed her surname.
But for people with serious resources - especially money - such a cover wouldn’t be a problem.
They would have found her very quickly, and the rest of the scenes would look like something straight out of
Scandal in Neon Tokyo.
The version involving her husband, attempts to steer him in the needed direction, seems to fit more with a personal revenge story from Rika, and resembles a “female pattern” of strategic thinking.
As for why she wouldn’t suspect her husband in all this, the answer seems obvious: the author made the protagonist extremely convenient for this role - his behavior could never pose a threat to her. Only Terauchi changed the situation.
If we look back at the school scene with the telephoto lens, Rika’s attention turned to the Freelancer, and for a fairly clear reason - his debts and his unwillingness to pay them.
She tried to find an explanation for Sousuke’s behavior in him. The Freelancer tried to pressure Rika
through her husband.
And as we remember, he was punished afterward. Yes, his wife took the initiative for her own personal reasons, but she herself almost became a victim of violence - under Rika’s guidance.
But her husband didn’t stop acting. And next, her attention shifted to the young teacher, whose connection to Sousuke, from Rika’s perspective, might look much deeper than what we were shown in the story.
And this happened right after the sports festival, where the protagonist revealed his face to the unnamed couple before the “horse-man” scene.
Immediately afterward came her response - the meeting and the manipulation with the pregnancy.
As for Shiratori, maybe she still doesn’t know about his connection to Sousuke, so his punishment hasn’t come yet.
Eventually we arrive at the trip and her escape.
She encounters a new threat, and in the context of her past almost catching up to her, and Sousuke likely slipping completely out of her control.
Shingo Mori, a man who hasn’t wronged her yet, makes a mistake.
According to the plan, he returns the SD card, but on his own initiative he publishes the bar video and perhaps had previously disobeyed Rika’s request to remove the fragments that compromise her - leaving them in, revealing them to Sousuke, and provoking her wrath.
The speed of the publication hints at this - it happened immediately after she left the room, perhaps even earlier, since Sousuke couldn’t check his phone while in the bathroom.
This is where Rika’s principle comes in:
finish the job with your own hands.
She edits the SD card, leaving a “gift” for Shingo, and prepares her escape route. She might even call those who could pick her up and shelter her.
In the end - Rika flees. She fails to find the true reason behind Sousuke’s change in behavior; her dark past is catching up to her; she has no other option. And most importantly, as a “queen,” she suddenly has no pawns at hand - the pawns she would sacrifice without hesitation the moment she needed to.
Her husband doesn’t return to the hotel room that evening. When Shiho’s friend arrives, it turns out that Shingo and his wife also left the room and disappeared.
There is no time left to think - Rika disappears into the darkness. Then comes the publication of Shingo’s “shaved head,” which destabilizes her even further.
And her call to Misato may be just another attempt to find out who exactly is responsible for what’s happening with Sousuke.
If we accept the possibility that she caused pain and loss to many people in the past - then it’s very possible she genuinely has no idea who could be capable of doing this.
At this point, she falls back on her classic approach:
if your stealth mission is blown, you must hide in the bushes and wait until the guards’ attention fades.
