>if these techniques and vulnerabilities were made public[...]

Should the government prove that it followed the law when investigating a criminal? Did they obtain the proper warrants that people recognize preserve stable law and order?

It's unreasonable to assume that the vulnerability, that brought this case to justice, is the last one that could ever be used. More so, if you assume that most people are good and a healthy society needs privacy, we now know that there is a vulnerability that will affect more good people than bad and we are duty bound to protect good people's privacy.

Checks on the government's power aren't there to let 'bad people' go free, there there because we know if we let the government's power reign free, more good people will be hurt than the few 'bad people' we punish.