I think the AI in the name AI Video Detector is referring to the fact that it detects AI, not that it is AI. I'm not sure though, it's just the first free one that popped up.

If you know of one that is more reliable or that you trust more I'd be happy to run the video through there- or you can.

I didn't really need a 3rd party site to tell me that the video is sus- it's pretty clear just by looking at it.