Finding and dealing with falsified observations

I have a related question that happens to have just come up so I thought I’d ask here since this post is still pretty recent:

What do people do when they find what looks like users cheating (for lack of a better word) on these assignments by posting photos that (I assume) are not actually what they claim to be? There is a university class project that has been generating a lot of observations - it seems they need 10+ observations of a variety of life (fungi, mammals, arthropods, plants, etc.), which is cool and I’m glad to help of course. We came across a photo associated with this project that appears to be an Australian (or otherwise non-native to North America) orb weaver spider. Easy to spot since there are only a few species of this very-recognizable genus in the area where it was listed and this is clearly not one of them. Looking through the user’s other observations I found several other suspicious ones. The questionable observations all have “Screenshot” as the source in the EXIF data, whereas the user’s other observations of common local things were all taken with the same model of iPhone. So kinda seems like they ran out of time on their bio class project and just found some photos to pad their numbers. Either that or they got really lucky to find several non-native species on the same day.

My question is: Is it inappropriate to report these to the project owner or maybe even track down the course instructor? I’ve never taught university courses or dealt with this sort of thing before, and again it’s just a suspicion. I couldn’t find the source images with reverse image search. A couple people mentioned it in one of the observations (something like “did you really take this photo in [state]? that would be an amazing find!”), and the user deleted that observation the next day, so that kind of adds to my suspicion. What would you do here? Is it none of my business or should I tell someone?