I missed the fourth quarter but it seems like that was another game that could have gone either way. Boston gets to play at home in game 6 but they'll only have the advantage if they come out aggressive. They need to set the tone right from the opening tip because there's no way Golden State wants to play in a game 7 under any circumstances.
I think the Warriors would be fine in a game 7 seeing that they would be playing at home. Boston probably doesn't want the series to go to a game 7 at the end of the day, which is unfortunate for them. Because if they want to win it all, they will have to win in a game 7.
While I generally agree with your initial statement, I also kind of disagree. The Warriors set the tone very early, and had control for most of the game. Minus a Boston run in the second half, they actually didn't show me anything to make me feel confident that they would end up winning the game.