Yup, sounds like a right royal wiener,

errrrrrrr, winner!
Hows the fencing? Is it time to upgrade to say a 8 or 10 ft fence? What about a blocking wall/fence on that end of the pond? A nice half moon gazebo .... Oh, the possbility's are endless to foil! I don't think weeping birch are tree's that get too overly big height wise.
Personally Scott, I wouldn't tell him diddly squat as of now, none of his buisness, invasion of privacy etc........
Yeah, I know what you mean though Scott, some people think they own there property and yours also...
Last summer when we went to yellowstone I remember seeing someone's home along the freeway with a small heard of elk, so he could have it worse ya know....
Could have been cows, pigs or peacocks!

The former being very smelly, the later being extremely noisy!
I can honestly only think of two reasons some one wouldn't be honest and forthcoming over the pesticed, either its a illegal one, or he's afraid everyone will want to know his cure all tree killer,lol!
Might ask about whats used for those certain pests he's supposedly spraying for. Another thing, the dept of agriculture will find out, they can test and tell whats being used.
*******
Fish,
I learned to use the database in self defense, but it helps me as others gain from my hard learned lesson. Don't know what the chem was in Darlene's case, but I can tell you it was very horrid stuff. Poisoning goes like this: Outright death's, survivors go through the normal, parasite outbreak, then secondary's ulcers and fungus (sap). But the poison used in Darlene's case caused the wens on her Oranda's to collapse, just like melting fat......

I think it effected there organ's badly.
It was very sickening and heartbreaking to see this!