Phil Brown deserved to be sacked. He only lead the organization to a single win over the span of 16 games, and they were nearly at the bottom of the standings. With the risk of being demoted out of the Premier League too great, Hull City needed to do anything to shake things up.
Yes, the sacking of Phil Brown by Hull City was justified. He did things that he should not have, and that this school believed to interfere with how he was doing his job, so he needed to be fired. They did not get rid of him with out a very good reason.
In any sport a coaches job is to teach and lead his players to victory while maintaining a certain level of professionalism. Phil brown was not doing either. His team had been on a loosing streak. At the time of his sacking the tigers were 19th in the Premier League and struggling.
Regardless of whether Phil Brown's new team is winning or losing, Hull City did what they thought was best for Hull City. They did so with more information than we have. The goings on behind the locker room doors will typically remain there, and the fans will be kept in the dark. His most recent professional and public failures as they pertained to the team were not likely the only thing going on.
When someone is as good and successful as Phil Brown, you don't just fire them when a few things start to go wrong. People like him know what they're doing, are good at their job, and when given the right chance will usually start to accel again. This was a poor choice.