I'm thinking about the concept of 'frenemies' and jumping to some unsupported conclusions.
In tech you may have a turnaround of weeks or months for some products. In automotive, you may plan a new vehicle for 5 years and then in some cases produce it for up to 10 years after that, and then continue to support that vehicle for 10 more years.
Also, automotive customers do not support the idea of moving quickly and breaking things (excepting some Tesla customers).
This leads to relationships like 'frenemies' not making much sense in auto manufacturing. If you can't trust the other party to be there for years, you don't start a relationship.
Now the mostly baseless speculation: It seems that Mark Fields felt that Ford brought a lot of value to a potential Ford-Google partnership. I assume Fields though Google would understand and value that as well, and it seems that Google did not value that, leading to misunderstanding and frustration.