You've got under 5 minutes to decide whether or not a widely reported critical security vulnerability actively being exploited in the while is severe enough to warrant taking down your site or not. The downside for taking down your site is approximately 0, and the upside is that you don't get shrekd
No security expert can or should work that fast. Its a completely reasonable thing to do given the hyperbolic reporting just in case it turns out to be true. Some websites being down for a few hours doesn't end the world