Japanese use a lot of back-channel chatter when they talk to indicate that they are actively listening (Auzuchi). This includes saying "Yes" to indicate "Yes, I understand what you are saying" instead of "Yes, I agree that we should do as you are suggesting". They may not always indicate disagreement by saying "No" either, but simply by not committing to your suggestion when its their turn to talk (or some other, subtler expression than "No", such as a head tilt and an intake of breath)
This active listening behavior has apparently led to similar misunderstandings before.
Of course, if you made sure you actually came to a clear agreement with the execs, it's an entirely different story.
After the meeting the customer was very upbeat but in the end the supplier never did anything they had promised.
It was interesting to observe this as a somewhat independent outsider. I came away with the impression that the people at the supplier had some disdain for their customer.
There was this one data center in Tokyo that we needed to put stuff into - and we needed a GPS antenna on the roof of the DC piped down to our cage...
The DC itself was the most aesthetically beautiful DC I have been to; Bamboo forest and waterfall in the lobby, black granite everywhere, the receptionists were two beautiful women... The place was pristine in look and super super clean.
We met with the execs that ran it and they agreed to all our requests - to pull lines from the roof to our cage, etc...
But in the end, they said yes to everything, but didnt actually do anything that was requested.
It was a waste of a trip (aside from the fun we had while not doing work), but it was stunning how much work was turned down based on them saying yes, but not actually doing any of the work requested...