I brought up bad luck a couple times in the Rangers series (which was more or less balanced by good luck), but the Caps are playing a game against the Lightning such that one bad bounce kills them completely. That's on them. It's a dumb strategy. You won't beat a good team often, particularly a good offensive team, when you score 2 goals. Especially when it takes a 6th skater to get a 2nd goal.
When they've played well they're creating chances, but they're not finishing those chances nor are they creating 2nd chances. Even when Roli wants to give them. It's hard to score on the 1st shot every time.