jinman,
Sorry I don't have names for you and that you think I am preaching junk science. I do know that I have heard of this locally in the past. People mow over the same areas and think they're safe, or they go a little too fast one time and then someone is finding them a few hours later since they didn't come home. Land changes, ruts form, vegitation hides the changes etc...
He can do whatever he wants with his rops, as can you. I am glad you are okay after your close call. I guess if a branch was low enough to hit the front of the tractor and dent the sides in if you wanted to mow there you'd cut it, or at least I would, so it makes sense to me that if it was going to hit the rops and I absolutely had to make that last close pass I would cut the branch down. An operator needs to know the dimensions of his machine. Chances are (and I am just speculating here, so more junk science follows) that if you are mowing that close to the tree line the ground cant be worked up as well due to obstacles, and you are likely to find a few whoopty doos and ruts anyway.
It is obvious from the feedback he got that he is aware of the intentions of the rops design and has decided to leave it down, so that is his call and yours in the end. I just enjoy reading all your posts so much that I wouldn't want it to stop. No offense intended.
I guess since his wife was a new tractor operator (and I am guessing at that too since I don't know if she has operated them her whole life) that it brought me extra concern as she may not be as used to the machine as he is.