He walked on Watford for Everton, regardless of the official ending there.
I thought he'd done it somewhere else but maybe I was wrong.
Perhaps thinking of Hull, as he was parachuted in on a 5 month contract to try and save them. He was seen as the 'next AVB' at the time and did well there considering the circumstances, so no doubt he might have walked anyway if his contract was longer, but it was the end of his contract anyway
The Everton/Watford thing was a bit weird, but I don't think it was Silva's "fault" in that sense. They said no to Everton, then the team went on a run of bad form so they (Watford) sacked him anyway. That is very much part of a 'Pozzo' way of doing things as they seem to hire a manager for each new season of weather, instead of each footballing season.