As to caching: to a certain degree, I doubt that, actually. When a Windows component has crashed, the same ones that I mention go through the whole process, it always informs me that I'm offline if I disconnect from the internet. For non-Windows ones, it always completes instantly, sends me no link, doesn't realize I've disconnected, and always says "success".
There's a disconnect here. If it's cached, it should say so, not tell you it succeeded when it didn't. Meanwhile, why do some detect internet connectivity and some don't? It's fully possible you're right, but I've seen no evidence of it.