Tom Clancy-esque plot twist - what if the US responds to a cyber attack against a State Actor (based on the best evidence at the time) when it was actually perpetrated by a non-State Actor (like say, a disgruntle ex-employee/s)?

The White House says the devastating cyber attack on Sony Pictures was done with "malicious intent" and was initiated by a "sophisticated actor" but it would not say if that actor was North Korea.

Spokesman Josh Earnest says the matter is still under investigation.
http://www.npr.org/blogs/thetwo-way/...e-proportional