OP, can you explain how you know for certain that this student claimed these things on their application? I assume you have heard rumors and not seen the app itself. You saw an online CV, but not the app. In that case, you are on thin ice to report it. Who knows if the rumors are true? What if the person spreading them has another agenda, or misinterpreted something they heard? Or if the applicant said he MIGHT claim these activities, but didn’t actually do it.
Also… my kids had ECs that no one at school knew anything about. Could be at least part of what is going on here. One of my kids competed in USABO, for example, and no one at school except her Bio teacher knew.