I work in a small technological company, less than 25 persons, in two different countries in Latin America, clients in both of them.
I'm in charge of operational issues, which means to install servers and software, giving support to problems and answer questions from clients. I have a team of four persons working with me.
Usually most cases from clients arrive and are resolved without knowledge of the CTO or the sales managers (one on each country). Only important cases are informed to let them know.
One case arrived the other day, regarding to a possible failure in a system a couple of days before, since we did not have enough evidence we could not give a quick answer. Then started the problem, the sales manager was informed of this issue and he quickly sent an email to the client saying that the problem observed was not ours. Later that day I informed to the sales manager that maybe we had a problem, but he chose to not make more noise about it. Since the client did not have a explanation to the problem, they continued investigating the source of the incident.
The problem is that this incident had a high chance to be repeated, because we did not have the whole solution at hand. In the meantime the client was gathering more and more evidence that it was our fault.
Few days later the incident repeated, with slight differences. This time I quickly told the client that the problem was ours and we had a diagnosis, hence a upgrade for the system would be available soon. Because the probability of repetition was high, and the client was already suspicious.
After that the system failed two more times with the same pattern.
Now we have the patch and the problem probably will be controlled. But I still have the bad feeling of having the sales manager answering support cases to calm the client whenever an issue does not have a fast diagnosis, or worse, having the customer sending incidents to the sales manager instead to the formal channel communication. Surely he thought that it was the best strategy to lie at that moment, but we did not have a decent lie then.
So the question is: How can I prevent the sales manager getting involved on issues of my responsibility while we keep a good relationship between us? He is in the other country, while the CTO is in my same office. Obviously, even though my boss is the CTO, the sales manager is more important than me in the company. Since the company is small, no written rules are available.