Were I belaying this guy, I'd have fed out a foot or three of slack on red, so that I could belay carefully on blue (which is protecting him from the ledge below). That way I could take in blue if he downclimbs, without worrying about pulling down on him on red. That also makes red easily available for a clip, and leaves red loose so it may not entangle him if he fell.
Ideally, the red would be between the climber's right leg and the rock. Michael is correct that red is highly unlikely to flip him in a fall; but the point also remains that the climber does need to at least be aware of both ropes. There's no way to tell whether this guy is or isn't aware of it, however.
Maybe I can clear this up - I was belaying the climber. If you look at how far right the last gear on the red rope is, you'll see it would be worse to have the rope run inside the right leg rather than over it.
There's clearly more risk of getting flipped sideways after catching a heel, but all of this is a moot point as the climber would certainly hit the ledge below him long before there was any tension on the red rope.
Given the amount of rope out, rope stretch during a fall, etc, i don't think that it can be ruled out that it would be possible for the red rope to give him some trouble. It might not flip him entirely upside down, but even getting your foot hung up and falling sideways wouldn't be optimal. In a case like this, i would have the red rope run over my foot, but in front of my shin. I usually use my shin to steer the rope where i want it to be. Then, if you fall your foot/leg can easily stay out of the rope.
I think that Anthony is correct in stating that putting your leg on the right side of the red rope would be worse. Surely you would clip an ankle. However, at the same time, you want to minimize any possibility of catching a leg etc, by not getting hip deep behind the rope. If you keep the red rope scooped near your ankle, you minimize the possibility of catching something on your way down. Just because in this particular situation you may hit a ledge before the red rope catches (which seems doubtful on a route as overhanging as FCD), doesn't mean that striving to always keep all variables in check is a bad policy.
Give the climber a break! You're looking at a snap shot of a climber in mid move. Taking into account the climbing position, position of the gear on both ropes and the position of both ropes everything looks fine to me. It could be that the red rope perhaps be 6 inches from what you may think is the perfect position, but there is nothing wrong with it the way it is. Furthermore the gear on the other rope that is off of his left hip in the flake is bomber and there is another piece just below that.