The barber probably did it. It was too convenient of a time for the barber to come in. Almost as if it was planned, and the response of the president was strange. Almost like a good cop bad cop act. The Barber probably was in financial trouble and in debt to the real estate president. In order to stay in business he had to help get the company land or he will lose his shop ( still working on the motive part) In order to rid the "black sheep" of the community he decided to kill the President in the Ramen shop. Whatever the reason he instead of letting Conan and company get the chopsticks from The President he instead offered them his. Why? and why so quickly? The owner and employee had no reason to kill a man in their own shop (it's bad for business), and the President had no reason to actually kill himself but get poisoned and sue is a different story. Actually i bet the Barber switched the poison in his shop to make sure he dies. The president probably switched hands to poison himself, not kill himself.
Idk for sure yet, those are random thoughts, but I'm sure i'm close
btw, if any of you have a deduction ready, be sure to play the Beat Conan Deduction game as well :grin: