You still do not get it

The case is about bankruptcy law.
Before filing the bankruptcy petition, the employee has lots of ways to collect his previously earned salary. However, after the bankruptcy filing in US or Canada, any effort of collection other than filing with the bankruptcy court would be estopped by the petition. The estoppell is a very wide one. It even applies in perfecting a lien, bringing action in any other courts, foreclosure sales, and etc. This is called Automatic Stay under 11 USC Sec 362. And there is penalty in bankruptcy code for willful violation of the stay, such as suing the company in another court.
So upon filing, the employee's only remedy is filing his claim with the bankruptcy court.
P.S. Bankruptcy is a total different ball game.