You know my opinion. While it took until the 7th for the wheels to come off, the guy was hit pretty hard all game long. Lots of line drives. Is that Roark or the Orioles lineup? The Orioles are ok, but they aren't actually anything special in the AL, so I'm going with Roark.
Yes, yes I know you all love Roark and have a giant Fathead of him covering your wall which you kiss every morning before going out to work. But here's a fun note about Roark that you never hear - it's possible only one other consistent starting pitcher has faced an an easier set of opponents in 2014. This stat, aggregate OPS of opponents faced, isn't an "end all be all" one so you don't have to (and probably shouldn't) take it as gospel. But Roark ranks so low in comparion to other pitchers the idea that he's had a bit of an easy ride, if not the easiest, has to be considered fact. I mean 35th out of 654 guys who have thrown a pitch this year. That's not something you can dismiss out of hand.
OK since you are wondering
Roark : .667
Fister : .703
Gio : .669
Stras : .690
ZNN : .690
Clippard at .719 ranks as the highest of any notable Nat. The Nats as a whole rank on the low end because the NL is going to be lower than the AL with all those pitchers and the NL East is probably the worst hitting division... well the worst hitting division when you take out the Nats, who the Nats pitchers don't have to face. Gio, you might notice also ranks on the low end which is kind of worrying given his up and down year but this is why I note that you might not want to put complete faith in this stat. I trust the history of Gio. With Roark the history is limited so I take a closer look at something like this.
Roark's next start, on 4 days rest again and against the Braves will be huge. Luckily for him - NL East - the Braves aren't all that good at hitting the ball. If Roark stumbles again there has to be a question f how effective he'll be come the stretch run, likely two additional starts away from his all time high in innings pitched.