I work out at the Oregon Country Fair, and we do Conflict Intervention Training every year. One of the more interesting and important things I have learned is how to make non-threatening/invasive statements.
"There is a tree growing there." is a strong and definitive statement and the response (even for a tree - remember this is the Fair!) could be "There's not a tree there!" and then you have conflict and disagreement.
However;
"I see a tree there."
"There's not a tree there."
I didn't say there IS a tree there, I said I SEE a tree there."
Conflict may continue, but it will be much less heated. Everyone is making a different mental map of every situation. It kind of reminds me of the party game "Telephone" where the message is utterly mutated my the time is passes through lips and ears.