While diving in deep into the Reactive Manifesto I encountered a link that resulted in the familiar no connection error. Well of course, I don't have a connection with my phone in the tunnel, so this is what I get. If the developers followed the manifesto however, I would get a different response.
This gets a bit into the heart and soul of reactive systems. Perhaps in a reactive design, the browser would do a few things differently. It might check for a connection first, then check to see if a DNS server is available, and do the lookup. If not available, it might give the option to try later automatically and let you know when the page is loaded for viewing. Why should the user wait and watch the progress bar while the page loads? Just deliver the page after it's done!
Think of some of the newer automated phone systems where the system will call you back when an operator is available so you don't have to drag on the line listening to distorted elevator music and the same repeated message until they can catch up to you. This is part of being reactive. If the phone centers were truly reactive they would be able to add operators as demand increased in order to decrease wait time/increase capacity. A browser might not be able to scale in a similar way, but it can behave in an asynchronous way with respect to the user.