A little too late for that? You're the boss, fire him! As an independent owner you have the implicit right to do so. You owe it to the health of your agency.
But there is another threat that is more difficult to detect and remove than a bad employee. One of your clients could be the culture killer. We as managers are not afraid of firing employees that damage our culture, so, what about clients that do the same? When pursuing new clients we have incorporated a series of measurements that we follow to determine if there is a mutually good fit. We look for risk takers and those that demonstrate a true desire to build the brand. But we don't always judge correctly and it can become necessary to let an account go.
For example, we had a client in need of a strong branding agency and the prospect of producing ground-breaking work was exciting for us. The problem was its "board approach" to creative approval. There were endless tweaks, changes and dictates. We were worn out trying to either accommodate or change the client's methods. Eventually, there was a very abusive interaction with the account executive, who was just doing his job by defending the creative. It became evident that this client's approach was damaging to our agency's culture. End of relationship, period. Turning accounts away is a rough decision, but can sometimes be a smart investment in the people of your agency.
In another instance, we had a sizable account and had launched many new products for the client. We enjoyed our relationships with the marketers of this company. However, after some time project after project was being asked for on a rush basis. Our assignments became less and less strategic and more dictated. What's worse is that the client began putting its projects up for "auction," playing agencies against each other in a game of financial limbo – "How low can you go?"
Since this was a large account, we hoped things would change, but the work was creating a growing faction within the agency. There were those who knew that they were "saved" to work on the more visionary accounts (that allowed us to build a brand) vs. those who were the "workhorses" of the agency, relegated to more executional (albeit more profitable) projects. I soon realized that I was putting profits before people. My bad. We ended the relationship. This decision has rocked our bottom line, but in the long run we knew that it would be more detrimental to allow this clients' regard of advertising agencies to control our culture.
I've since learned the value of taking the time to regularly re-evaluate client relationships and ending the unhealthy ones. While there are certainly relationships worth trying to repair, there are those that simply must be killed off. You can only benefit by ending the relationships with culture killers and in turn protecting the people that are your agency.