Background: We submitted an engineering product to the client, who then has a team review our submission and provide comments which we must resolve. One particular reviewer, Andy (not his/her real name), has been very difficult, and even combative about resolving his comments. He's earned a reputation around the office.

Today I had to call Andy to ask a clarifying question. I anticipated he would be very difficult so I asked the Office Manager (OM) to tag along just in case, so I was on speaker phone. Andy was actually very calm and reasonable, and everything was resolved quickly. I put the receiver down, and proceeded to press the "call end" button, however, between putting the receiver down and terminating the call, my OM started to say "He's a pussycat, I don't know what your problem is" with a joking and jovial tone. 

I am terrified the call ended before "cat" and that Andy heard it! **Is there a recommended practice for handling this?**

As soon as it happened I mentioned that the line was still live when the OM made his comments, but he didn't seem worried, so I'm not sure he fully grasped the issue. 

Reasons I'm worried, even though I didn't say it:

1. It was my call, I was the primary talker, so I could be attributed
2. Andy is not the type of person who will just laugh this off, he's shown himself to be spiteful on several occasions
3. Our project team is small enough that if this comes back around it will impact everyone