The Caps have good offensive players and great goaltending, so it should be expected that their PDO will be higher than most. Getting outshot this badly yet winning by 5 is just not sustainable though. The top-6 needs to tilt the ice more, especially the top line.
Winning by 5 goals isn't sustainable at any shot rate. People are looking way too much into the shot attempts for this game. As Hive mentioned, shot attempts were even until Washington went up 3-0. After the lead was built the Caps were content to absorb pressure and look to counter.
The Kings throw shots on net from every where because they have low end scoring talent. For a team that bases their success off of physical play, shot volume, and sound defensive structure, their team defense was was pretty bad today. Caps also can match them physically while having a lot more weapons up front. For as lopsided as the shot attempts looked at the end of the game, I never felt the Caps weren't in control of this game.