Pretty sure Hughton will pick whoever he feels improves the team. Even the Limitations Act 1980 allows for a statute period such as in Tort - 6 years, contracts underhand - 6 years, personal injury - 3 years, defamation - 1 year. A tweet 6 years ago, deleted and apologised for would appear to be case closed.
While it may irritate Hughton, as long as Duffy does it on the pitch, then I think he'll manage him accordingly. Even Sir Alex tolerated some incredible behaviour if the player strengthened his team. He was only ruthless if he thought he had a better option at hand.
If Shane whangs a careless backpass into the path of an unnoticed oppo forward with a minute to go at 0-0 in our first home game in August he's in trouble, whether or not he has a big copyrighted signature love bite on his neck....