I know someone who flat out lied on their resume and sent them to several top colleges. It added up to 80 hours a week outside of school. Admissions and future employers aren’t stupid, I’m sure they see a handful of applicants like this. The funny thing is, I don’t think the applicant wrote any essays on extracurrics. That may alarm admissions. You’d think someone who does 80+ hours of volunteer/club work would have something to say about it in an essay. Anyway, I wouldn’t worry about trying to get them caught- it will only hurt your friendship. Unless you want that friendship to die off. In the long run you’ll be the honorable one!