It's been left very ambiguous as to Bob's condition. In the beginning of the episode he said "One more" or whatever, to Sasha after a kiss, to establish it was a "thing" with them. So that doesn't necessarily mean what people are assuming based on something else *wink wink nudge nudge*.
Only thing that really suggested it to me, and it might have been my mind assuming from crap I know based on something else we'll pretend doesn't exist, and loosley extrapolating from what we didn't see that happened underwater, is that he had a very slight limp on his way out of the church. But what gives me pause is that they will NOT let Gareth and the rest off that easily. They are likely going to be a menace to the group for a good part of the season.