Hilchos Rechilus, chapter 9, section 4

Even though saving Shimon is a great mitzvah and leads to peace, one must be very careful
to only speak to him after considering whether Shimon will avoid going to the place alone or do
something else to save himself from quarrel. For it often happens that Shimon will become angry
at Reuven because of one’s story and deliberately go to fight Reuven leading to even greater
controversy.