[absolutelastone]

You always need to be careful when it comes to customs really. Some minor things like certain foods and OTC medicines can have big ramifications in many countries, including losing your visa. If you're a business person counting on using a multi-year visa to do your job, you can screw up your career by getting it revoked.

Of course I think people should get second chances, especially naive students. The professor should also have been mindful of this risk and made sure she complied with the rules too.

[lofatdairy]

Completely agree, I think that an abundance of caution is extremely important to practice when engaging with these systems, especially given the political climate. I just think that discussing counterfactuals in this particular case is unproductive and the original comment needlessly insensitive.