Use of non-polite form between Japanese companies

Question

I'm reading the novel 下町ロケット now and one part that really surprised me is when several of the members from one company speak to members of the other company without using 敬語 (for example "やめた方がいいよ”).

The overall context is that one company is being forced to use the other company's technology because the second company patented the technology first. They are in the process of running tests against the part (a valve) and want to see it fail so they can barter to just pay the patent fees and use their own technology.

I know that using non-polite forms to someone on a 'lower' level of the same company is common, but I thought that between companies polite language was almost always used.

Is this dialog exaggerated for effect, or does this really happen in real Japanese business interactions?

Edit: With regards to broccoli forest marking this as a possible duplicate: While the referenced post is informative on its own and is about the same novel, it doesn't answer my question of how common this sort of thing actually occurs in real life. Also in the dialog I was reading there was neither 丁寧語 nor 尊敬語 (it was with a different company [帝国重工] than the one referred to in that post).

I know that speaking in non-polite Japanese can be considered rude, but I want to know how a realistic depiction that is compared vs. an over-dramatic one. Basically I'd like to ask: is this something I would ever experience in real life, in particular with regard to two companies in a business relationship?

Answer 1

日本語でごめんなさい。

「下町ロケット」は全体としては臨場感のある小説だと思います。でも、物語序盤の徳田のようなしゃべり方は、恐らく流石に非現実的であり、フランク過ぎるだろうと思います。彼は都心の大企業の重役です。取引先の社長に対し、あそこまで重たい話題を、この口調で告げる人というのは、現実の世界ではちょっと想像しづらいです。同様に、物語中盤での、佃から帝国重工の財前に対する口調についても、非現実的なほどに失礼なものだと感じます（現に、財前はずっと怒っている描写がありますし）。

この小説は「下町」というタイトルではあるものの、年商100億円以上の、そこそこ大きな企業のストーリーです。なので、現実の会話はもっとビジネスライクだろうと思います。どちらの立場が上なのかを読者にわかりやすく伝えるため、口調にドラマとしての脚色が入っているのは、間違いありません。

ただし、これはあくまで「都会の先端企業同士のビジネス」に限った話です。本当の下町、本当の田舎に行けば、ビジネス上でもまるで友達や家族のようなしゃべり方をする零細企業の役員は、たくさんいるだろうと思います。田舎であればあるほど、コミュニティが閉鎖的であればあるほど、敬語は使われなくなる傾向にあります。田舎に行けば、商店の店員やタクシーの運転手ですら、客に対して敬語を使わないことが時々あります。（もちろん、そういう人がこのサイトでこの質問を見つけて回答する可能性は限りなく低いですが…）

Answer 2

For example 三菱 is big company group (really 帝国重工 is 三菱重工). In japan there is a phenomenon called 下請け叩き. The famous big companies often control small companies. Many companies dislike big companies. I watched that drama, and thought it was interesting and realistic. I think that real parts of that drama are some parts of occurring various troubles on component development.