We know he's a good actor, but he's certainly putting on a performance here, if that's what it is. He had the tournament doctor out and the tournament trainer after he lost the first set, got some supplements, painkillers, whatever. They took his pulse.
I agree that he would do well to bail out and get to Paris, though his draw looks so nice, he doesn't really need the prep. And if this is the strategy, to play sick, it's a good one...you can withdraw, but no injury. If he really IS sick, he should recover in time for Paris, or, anyway, he could play sick through the first week, with that draw he got.