Even if they talk about it, its not like the second place you accepted will rescind the offer.
Do you really think professors are going to waste their time trying to track down a student who changed their mind about and offer and then figure out who to complain to?
Any by the time you graduate 5 - 6 years down the line, no one is going to remember it. Also, if the second offer strictly dominated the first most people would understand why you did what you did.