So the conservation officer conducted a quick investigation and the two troopers didn’t/wouldn’t as to the validity of this man’s story.
Something isn’t being told.
The conservation officer was not looking for an arrest and the two troopers were.
Not all troopers are Sherlock Holmes.
I have found (and pointed out) evidence which troopers had overlooked (including, in one case, another involved vehicle) which seriously changed the interpretation of events at an accident scene.
If the troopers couldn't be bothered to cross the road to look for evidence of vehicle impact, they did a crappy job of investigation.
If they thought the guy was out picking off deer with a handgun, their interpretation of events is shaky anyway. (While there are a rare few who might be able to jacklight deer with a handgun, they are a very small minority).