A common issue in construction is that a building is not going to be built by the investor company, its going to be built by the investors shell company. And since the investor company is not a mason/lumberwork/foundation company, they are going to hire other people to do the work, which is also going to hire other companies for specialist work. A few might spot the issue here. If there is a different company doing the outer shell and moisture barriers, then the company doing the drywall or the foundation has very different responsibilities from if it where just 1 contracting company or one parent company doing all the work.
So, why a shell company?
So if there are large legal demands for quality & health issues within the warranty period, you can and will declare the shell company bankrupt. Now, this do not free up the parent company entirely, but it means any larger warranty claims will then have to go trough courts on a far less automatic less burden of proof on the suing part.
Now, there is a far more prudent example of what the original poster in this chain is talking about
"Ryanair has historically utilized a contracting model where pilots are engaged as "self-employed" directors of their own Irish Limited Liability Companies (Ltd), rather than direct employees. These pilots, sometimes grouped with others in similar setups, work via agencies like Brookfield or McGinley, supplying services to Ryanair"
This is illegal in several parts of EU, but its also partially legal in several parts of the EU.