14 minutes isn't excessive playing time for a guy playing on the 3rd line and getting some pp time. And I don't think all of those 14 minutes were by design. He took 2 or 3 extended shifts where his linemates changed and he didn't.
It isn't excessive -- but it isn't diminished, either. It seems as though he wasn't at all protected (which luxury one has when the score is 4-0.)
As I said, I didn't see the game other than the highlights, but I'm wondering if some of those extended shifts were because he was the "chaser" to protect a line change. When a line's shift ends with the other side having gained control of the puck but on their side of center ice, one person commonly dogs the puck carrier, trying to drive him back toward his goal and, ideally, behind it so that his line mates can get off safely and the replacements can get into position without the puck carrier being able to find a teammate hanging out at the Caps' blue line. Then when the new line is in position the chaser peels off to the bench and the last change occurs. This role is especially important in period 2 when the long changes occur. Wilson is almost always in the chaser role for line 1. Backstrom and Oshie share those duties on line 2 for the most part, with Oshie I think having the majority of the responsibility, though now with Stephenson on that line, he takes turns at this as well. And Burakovsky, when he is on line 3, commonly handles chaser duties. Line 4 rotates the most on this; Beagle, Smith-Pelly, or Chaisson might be the chaser in any particular situation -- whoever is most conveniently positioned.