Well for a start there was an x-ray which showed a tear in the muscle, so unless he so committed to fabrication he is willing to commit forgery, then I think we can assume there was an injury. It was obviously not nearly as bad as first feared as any movement would have been difficult, let alone playing tennis against the world no.1! Thing is Andy like most sports people is constantly fighting niggles and minor injuries and having had a few nasty ones, particularly in the first few years of his professional career he lives in fear of a bad one, this obviously felt like one when it happened, but as recovered and tested it, proved not to be - Voila!
I also think for the above reasons, he is perfectly suited to make the right choice in whether to play or not, as it is a minor injury, anything like a true inversion ankle injury and he'd be booking his hols to coincide with Wimbledon.
Common sense at last! In his on-court BBC post-match interview with John Inverdale, Andy made not a single reference to his ankle. Just said he was glad to get off the court quickly against Roddick because he's played a lot of tennis recently. Sounds like it's troubling some of us more than it is him!
Fortunately at least there is a gap before Wimbledon in which any niggling residual problem can be more effectively dealt with. I expect him still to be wearing a brace during Wimbledon, but probably more as a precautionary measure rather than for more sinister reasons.