Community complaint re: company car

Hi, I am an RN, and have worked in home health for 18 years and I have never had an incident like this. Has anyone had something like this happen?

Here is the story:

A few days ago, I stopped at a fast food restaurant to use the bathroom. I got in, did my thing, and left right after.

Not more than two hours later, I got a call from my supervisor letting me know of a very bizarre complaint. He told me that someone had called to complain that a woman was yelling at a man with a walking stick in the parking lot, and both got in my car and left. The person who called claimed to work with the traumatic brain injury waiver program and even gave a full name. She took a picture of my car and forwarded it to my company.

I was absolutely flabbergasted, to say the least. Not only do I not have a patient with a walking stick, there is NO earthly way I would ever take a patient out in my car, anywhere. The only passengers I ever have in the car are my family(we are allowed to use the company car for personal use) or a trainee. What's really odd is that the picture showed only my car-no yelling people anywhere nearby. The description she gave of the yelling woman was totally off, too. At first I thought maybe she saw these people in the parking lot and it looked like they were heading towards my car, but after thinking about it some more I'm becoming more convinced that the whole thing was made up by someone who had a grudge against our company, saw their car in the parking lot, and saw an opportunity to get back at us.

Bottom line is, my supervisor is thinking like I do, and nothing is going to happen, but the fact that I had to even take time out of my day to even talk about this was just really ticking me off big time.

How do you protect yourself against these kind of things? Do you have to start recording yourself, wearing a body camera, etc? ?, just being paranoid, I know, but it irked me to no end! I mean, I just had to use the bathroom, for crying out loud!