[dankohn1]

Actually Google did find Heartbleed (along with Codenomicon, who discovered it independently). [1]

[1] http://en.wikipedia.org/wiki/Heartbleed#Discovery

[ScottBurson]

And Codenomicon apparently found it by fuzzing [0], though I haven't seen any details.

[0] http://www.codenomicon.com/products/defensics/