Graffiti is vandalism, i.e., a property crime. Poaching, by definition, is hunting an animal that is restricted for varying reasons, from being a protected species to herd management, etc. It's effectively taking something that doesn't belong to you.

In this case, he did break the law by picking mushrooms where it was specifically prohibited, and it would be reasonable to cite him for that fact.

But it wasn't about theft, it was about the fact that he wanted to ingest a compound which would alter his state of consciousness. That should not be a crime.