I've seen more than one lawyer who seems to think that the exception is implicit, which would mean the search is not invalid on its face.
I can't see that holding up once challenged, especially if they find evidence of a crime by someone else on that computer for an unrelated matter.
Source: http://volokh.com/2010/04/27/thoughts-on-the-legality-of-the...
This part is my own interpretation, but I think it's reasonable: given the lack of direct precedent, the CA court that considers this matter will probably consider the legislative intent behind the law (Gizmodo is out of luck) and look to how similar laws have been interpreted (again, Gizmodo is out of luck).