I would report him but also tell  the conservation dept the situation you are  in  . They have probably dealt with similar situations before and know how to handle it .

Sounds like the guy is already ticked off at you so I'd absolutely turn him in. I see he's already being investigated so my advice is probably not needed.

 

If not send me the info/FB page and I'll go online and report him myself. He sounds like a world class jerk.