Well, actually in all platform, Blockchain, Game, Internet, and everything that contains Online/Offline thing is always can be fun. But also give some troublesome. And every "Online" activity always use "Request" and "Response" which is the simplest way is by using ping. Different condition (Online & Offline) "Always" give different results. This is why its impossible to create it in offline.
Or do you expect something like temporary cloud services ?
So when we send bitcoin, its only send to the temporary folder to be save the record, and after we connected to the internet, it will just response and we don't need to open the apps/web and send it again ? i think this would make some crash/bug