Everything in the Okida household seems to be controlled by a computer, from accessing doors to the air-conditioning.
Conan comments that Okida sweated way too much during the night considering the house is set to maintain a specific cool temperature.
Conan's notices wilted flowers on a table and finds a receipt for the bouquet in the trash. The flowers were purchased the day before, so it doesn't make sense for the flowers to have already wilted so much. Examining the chocolates on the table Conan notes they have all melted into lumps.
Okida's sweat, flowers, and chocolates imply that the temperature control in the house changed the night when Okida died, but Aslan, the Himalayan cat, appears to be fine. According to what Ran heard from Tokito, cats like Aslan need to be in a relatively controlled temperature environment.
Miura explains to Conan that Tokito used to be a programmer for Okida until Tokito and a friend decided to set out and form their own company. The company however ended up being a failure and Okida "graciously" allowed Tokito to work for him again as his chauffeur.
Tokito seems enraged remembering a "certain man" who drove his business partner into committing suicide. Conan asks if the "certain man" is Okida, but Tokito doesn't answer.
Agasa confirms Conan's theory that someone could hack the Okida household to change the house's settings, but it would have to be done by someone really versed in programming.
When Conan visits Tokito's apartment he steps on an unusual "flake" thing. Upon returning to Agasa's house, he realizes he stepped on something else: a cat hair.
Thanks to Agasa, Conan realizes that Tokito must've programmed Okida's computer system to heat up the house really quickly and then cause a sudden drop in temperature. This sudden change in temperature is what triggered Okida's heart attack.
The flakey object Conan stepped on in Tokito's apartment was actually a piece of cat litter. The cat hair on Conan's sock was also from Conan's visit to Tokito's apartment. To protect Aslan from being involved in his revenge scheme, Tokito took Aslan back to his apartment so the cat wouldn't get hurt.
Tokito's motive for killing Okida was revenge for his business partner who committed suicide.
