When talking to clients or potential costumers, companies should take several things into account, including:
1) When taking your team to a client, do not take a bunch of geeks with an "I'm right, you're wrong" kind of attitude. If they're right, they'll upset the client; if they're wrong, they'll just show how lame they are.
2) Likewise, if you're taking some commercial type of people with you, do not let them throw excuses in the air for things that are not working, because it's hard to guess things like that without technical knowledge. The client might not know as much on the subject as your technical people, but he might know more about it some commercial guy.
Yes, this has just happened; fortunately for my reputation, I was on the client side