Err, what? The constitution is itself part of the law. If a legislative law is ruled unconstitutional, then that legislative law is invalid, and always was. Ergo there was no authority to perform the searches they did.
You seem to be implying a different model under which unconstitutional legislative laws would remain in effect, but the people who passed them would be personally responsible for having gone against the constitution.
These people didn't swear an oath to the constitution, the people who wrote the unconstitutional laws they are enforcing did.