I don't really have strong views either way on this topic but...
Hair had a right to call Pakistan up for ball tampering. If he feels that the ball is unfit and has been tampered with, then it is his decision to change it. I think the problem arose at the five penalty runs, because at that point, a simply ball change becomes an accusation of cheating. Perhaps this area of the rules needs to be looked into. Pakistan had no right to stand in protest, since the rule of the umpires should not be disputed by the players. The umpires should have the ultimate power and the players do not have a right on the field to challenge it. If an umpire does something which is clearly out of order, then they will be pulled up for it by the Match Referee or the ICC, the players do not need to act to show their dismay - that is what media conferences are for.
Assuming he was wrong, what difference does it have to a bad LBW decision? It is not as if Pakistan have an innocent history in terms of ball tampering. I have seen footage of both Waqar and Wasim scratching the ball with their nails and Imran Khan has admitted to the act in one of his books. This is not senseless descrimination, this is sensible descrimination. If a team has players who has ball tampered over the past two decades, it is not unreasonable to pay extra attention in case they do in a third.
I think that in televised games, they should have a camera which follows the ball at all times; whether they implant a tiny tracking chip in the centre of the ball or someone has an extremely boring job is irrelevant; it is a necessity these days as the rules stand.
Hair should not have been banned, but realistically speaking, there is no way that he can fully command respect from Pakistan nor can he umpire a game without being under scrutiny and almost stealing the limelight from the players. An umpire needs to be nondescript and this is no longer possible with Hair. I don't think that he should have been reinstated so quickly, perhaps he should have umpired more low profile matches first.