Husband yelling at his Clients

Hubby owns a construction company and he’s managing things from home since we’re still recovering from Covid. So I hear him yelling to one of his clients on the phone because he’s complaining. Husband tells him that he’s sorry for being upset but the project isn’t moving forward because the client has some setbacks with his other hired crew and my husband is getting the complains.

I then, told him he cannot yell at his clients like that no matter how heated or upset he is because if he continues this road he’ll fail miserably. He’s convinced though that he won’t let his customers walk all over him and he’s got the right to be yelling. Who is in the right here? Is this acceptable behavior?