What happened to "innocent unless proven guilty?"
This is more a matter of probable cause rather than of having the assumption of guilt (it was a search, not a trial). Still, I cannot for the life of me see either how there was sufficient evidence for probable cause or that the means used should be considered reasonable to gain access without a warrant. Of course, I am not a lawyer, but if you have to have a legal expert to differentiate between what is a reasonable expectation of privacy and what is not, there would seem to be a problem.
My guess is that this or a similar method will be tried again but will most likely cause the case to overturned if it goes to a jury trial or a federal appellate court.