Is what the partner did—concealing his identity in a business transaction outside the scope of the company's operations, where the company became a supplier for it in exchange for a percentage of the profits—correct or not? And is this considered greed or lawful provision?

As long as you conducted the transaction through the company, you are not permitted to allocate a commission for yourself without the permission of the other partners. You must inform them of the true nature of the matter. If they agree, then so be it. Otherwise, you are not allowed to take a commission for yourself without their knowledge and consent. However, you have the right to request a commission for any additional work you perform for the company that you did not volunteer to do.