When I got home from the AR my rear tyre looked a bit melted, but I was tired and didn't take much notice. When I went to ride to work I discovered it was pretty much flat.
I took the wheel off this evening and discovered five small nails in the tyre, at least three of which had penetrated the casing. They're shown here on a 2p coin for scale.
One or two I might regard as misfortune, but five looks like someone has been putting nails in the road.
Obviously I've got no idea where I got them, but I'd suggest checking your tyres in case it was along the AR route.
Keith.