For schooling and academics, yes there is an official system that they use (the name is slipping my mind) that they verify transcripts against. It goes by SSN which is required wherever you go for school if you're a US citizen (not sure about internationals if they have student-visas or whatnot). As for the other stuff, it's sorta obvious to tell when somebody's lying when they're talking to you about something. If somebody says they've done 500 hours of scribing but in reality only did 100/200, their knowledge base and their capability of talking/elaborate on what they see will be significantly limited. I know for a fact when I was an early scribe I was sort of unable to really say anything about the healthcare system/medicine ect, but now with >2000 hours, I am pretty confident in what I say and it's expressed through the way I talk/elaborate on it.
Also, remember, interviews are usually 30-45 mins (maybe 1 hour max). You're gonna be asked the basics, why DO/MD, why this school, why medicine, what makes you think you're ready for med school ect. That itself if it's a conversation takes a good chunk of time. Couple that with your questions at the end and that gives them probably 5-10 minutes for other questions on your app (assuming it's with them). For them to then elaborate on your application I think does take some time. If there's an overly glaring discrepancy then they might ask you. It also depends on the activity. For instance, for my senior year, I had >100 hours of volunteering, while working 25-30 hours/wk in the ER, while doing research/internship and doing well in school. That's a LOT. But those activities are all unbelievably easily verifiable (my internship and research was on my transcript because it was academic credit, 2 of my LOR's came from physicians I worked with who both wrote about how much I work and balance my life). The 100 hours volunteering are recorded on a database through my fraternity, and my one trip volunteering in NOLA is easily verifiable by making a call to my contact I listed (the chaplain of my school). If the activities are easily verifiable, then I don't think in their minds it'll be cause for suspicion. But if you give a sketchy answer, then beware.