ORIGINAL: HuntingBry
I do a lot of hunting in suburbs and I'm sure you know that they will pay you no mind if you're 50 yards away and cutting the grass or raking the leaves, but as soon as you stop or step off the cut grass into their territory they are on high alert. Good luck if you go for it, and let us know how you do.
Same thing here. The landowner says they watch him mow the grass from close range with no worries, but let me take one step in the woods and they're off to the races!
If I was in your situation, I'd say go for it. It's not the same as opening a window and shooting, it would require you to do all the right things to actually get with-in range. If it fails, he'll probably hang around and be bigger next year!