Even if the only result is tossing the evidence that will still incentive Parallel Construction, which has been going on for a long long time.

The legal System is setup to encourage this. The only way to prevent that would be independent audits of all investigations which would be both expensive, time prohibitive, and over time the "independent" auditors would be corrupted leading to the need for auditors of the auditors, etc etc etc

it is the "who watches and watchers" problem, you find a solution to this you let me know because you will be a very rich person.