It would require trust to a certain extent. If a trusted 3rd party would take the responsibility, then they first need to establish trust. The 3rd party would need to be public and transparent to maintain trust. They would take a small fee from the employer to cover costs to run the service. Also the multi-signature transfer option would not require all participants but a majority. This would prevent any single authority from taking the funds. Think of the multi-signature transfer as a safe that has multiple locks. Trusted people will have a key to one lock on the safe but cannot open the safe without a majority of other trusted individuals. One of those people would be the employee.