A few of the problems:

1. The bottle of alprazolam is clearly marked TABLETS — yet when Tess and the boss-mother take a few, they’re huge red-and-white capsules. Alprazolam comes only in tablet form, never in capsules — and any doctor, pharmacist, pharmacy tech, or person who has been prescribed these would know this, as would some other healthcare workers. That’s a pretty big chunk of the viewing population who aren’t going to swallow (no pun intended) this lie.
2. Some powdered meds inside capsules don’t dissolve, which I learned when looking after someone who was ill and had trouble swallowing. The writer and producer should not have relied on this clumsy device, esp. bc (as noted above) ALPRAZOLAM DOES NOT COME IN CAPSULES.
3. It was the height of schiddy storytelling for Owen to explain to Peake’s character exactly what had happened with Amy. Good writers find a way to reveal crucial plot points from the past; even a flashback wd’ve been preferable to this.
4. It was BEYOND the height of schiddy storytelling for Owen to halt his frenzied killing of Peake’s character long enough to make sure she knew exactly every awful thing he had done re: Amy. I mean, come ON — if you’re intent on killing someone in order to save your own skin AND you want to be quick about it in order to avoid suspicion (it was daylight, his car was still in the neighborhood where her wife was hanging with her pals), you’re not going to engage in 30 seconds of exposition.
5. I completely DO NOT BELIEVE that the police found no traces of attempted strangulation on Amy’s neck. If the pressure on her neck was intense enough to cut air and lead to her death, there wd’ve been marks.
6. I completely DO NOT BELIEVE that the police found no trace evidence of Owen on ?Maya? — he picked her up and carried her for several feet.
7. How on earth did Owen enter ?Maya’s? house when Peake’s character was there looking for evidence? The door was locked, yet he somehow just materialized — bc the plot required it. Schiddy, schiddy, schiddy, lazy “Let’s just rely on magic” storytelling.

Very, very, very bad thriller that should NOT have been green-lighted in this state. A rewrite was in order.