TOR exit nodes are more likely to be flagged than VPN servers.

Though even for accessing TOR, using a VPN is a good idea. If you're planning of doing stupid things like mailing in a bomb threat to delay your exams because you haven't studied enough and you're using TOR, the usage itself will point at you if you're the only person using it. Had they used a VPN to access TOR, they wouldn't have been caught that easily.

[1] https://www.forbes.com/sites/runasandvik/2013/12/18/harvard-...