There Is Something Bothering Me This Morning

I woke up this morning with something nagging me in the back of my head, and it's really starting to bother me. I have pretty much pinned down what the source is, and its source is a comment that my manager made to me yesterday. We've been having some issues with this particular client on this project. Some of it due to our own mistakes, and some to their mistakes. However, the comment that's bothering me is this "There have been some things that have been said that have driven the state into a frenzy, yourself included. They said you said something couldn't be done because project 'x' was more important." I'm pretty sure I know why I'm bothered by this statement. I wasn't chewed out for it, which is a good thing, but I'm really bothered by it because I know I didn't say anything like that. My father told me that the only thing you have in the contracting business, or even in your professional life, is your credibility. I've taken this advice, cause I know he wouldn't lead me wrong, and realize there is a lot of truth to that. More than anything else, I am bothered by the fact the client would say something like that, especially when I'm 99% sure I didn't. This shows me that this client will do anything to ensure they are right 100% of the time. I'm willing to give some benefit of the doubt, but not when it comes to something concerning my conduct. I feel this has compromised my credibility to a certain degree. This client has been stressful, and I'm debating whether or not it's really worth all this agony and stress.