A: I'd say he's pretty shy and trying pretty hard not to get it wrong. Probably trying not to stare and maybe he's just not comfortable at the moment. It wouldn't be a lack of interest. If the bloke wasn't interested he'd let himself go a bit and relax.
A: I don't think you stuffed anything up at all. It can all be fixed if you stop being awkward around him. Be friendly to him next time because its quite likely he expected you to follow things up and set up a specific time and date or perhaps he is a little bit shy of you but still wants to do... more