If you keep your peace, you give up all claim to complain about being ignored. If you don’t make a fair case in your favor, you have no right to appeal. If someone doesn’t agree with you, but you don’t let them know, you are a coward to make known your final decision after the fact.
Learn to identify people with these “quietly hot tempers”, who don’t speak their minds, but then want to flee across the ocean to give their rebuttal where no one can dissent or object. These are revenge-driven weaklings. Do not be one and do not work with them. Their lives will be petty and small as will be the things they complain about.
Only hardship can teach them; do not try to counsel them. Let them be alone and constantly extend the one thing they lack: ongoing relationship. Send them a Christmas card every year. Drop off a box of blueberries when blueberries are in season. Extend benign, reasonable, harmless, and normal acts of an average friend and neighbor. Make sure such people know they are not alone. Don’t give up on them the way they pretend to give up on the rest of the world. And, don’t ever even once invite their wrath of one-way silence by trying to solve a disagreement in a useful manner. Just be a non-threatening friend from the closest distance they accept.
But, you yourself, never become that person. Speak your mind—kindly and diplomatically of course. Act with dignity in every way that you can. But, give people a chance to reason with you. Allow everyone the opportunity to persuade you. You don’t know everything. Even if the other guy is wrong, allowing him to speak persuasively—and engaging him in discussion while he does—will you help to strengthen your own opinion if nothing else.
Take the high road where disagreements are concerned. Be strong enough to welcome dissent. Let people know where they stand with you, simply for their information and without being hostile. Let others tell you where you stand without feeling resented. Thick-skinned, strong-standing people, after all, are naturally more effective and have few worthy adversaries to contend with.