Nah, I'm not satisfied with this. It's too superficial. In my opinion an obsessed person doesn't give up so easily. In this episode we even heard he's been burning money like crazy in his obsession. Not to mention 100 appropriate, uncontaminated samples would also take a lot of effort. When you are hell-bent enough to ruin the rest of your life by committing to murder, you are more likely to be full of doubts, not full of relief, at least after a night or two's sleep. Aqua, however, doesn't seem to possess a single doubt (related to that). I'd have already forgiven the plot if, during this ep, Aqua had started to think about it again. It's not even in his personality to be a cheery fellow who quickly moves from one thing to the next.
Akane, with her psychoanalysis skills, was depicted as intelligent from the beginning, even if not entirely stable. Good consistency. Aqua and Arima's date was a good watch, since interestingly enough we don't really have that much intimate scenes between them, despite Arima having been in love with Aqua ever since they were both tiny child actors.
Other than that, that restaurant... Nothing but meat and sauce? As much as I like good meat, it would feel a bit weird to eat such a meal, with no plant matter on the side.